nVidia GeForce 7950GX2 overclocked by XFX

We interrupt our Computex 2006 coverage to bring you our look at the overclocked GeForce 7950GX2 graphics card from XFX.

Manufacturer: XFX
18 minutes & 54 seconds read time


Overclocked 7950GX2 by XFX in the house

As we roll into June like every year it is very exciting. Why? It is Computex time again and while I am sitting here at our labs in Australia and not in Taipei, I find myself not all that phased because we get to play with something hands on that is a bit more exiting then a plane trip.

Only a couple days ago at Computex, nVidia launched GeForce 7950GX2 - we all know about it, we even knew about them before the 7900GX2 was available but just how good is nVidia's second attempt at SLI on a "single card" going to be? We shouldn't call the GeForce 7950GX2 an SLI part but that's pretty much what it is. The 7900GX2 which we looked at last month had some niggling issues but overall wasn't too bad when gauged as a sign of what's to come.

There is a bit of talk around about the 7950GX2 though - while anyone will be able to go out and buy two GeForce 7950GX2 cards which will result in a total of four GPU cores (or Quad SLI), will you be able to run them?

We still aren't sure as unfortunately we still have not got that far thanks to the huge pain in the butt it has been to set the thing up. We put one card in initially (two cores, so we are clear!) and started benching; we were going all fine then after a reboot after a number of benchmarks, it went all down hill. BSOD, freezes in Windows install, freezes getting into Windows, crashes after driver install and more. Installing an older card like the 7800GTX found the system running no problems for a while then it all started over again. At the moment though we think it has come down to four things - the 7950GX2 being a bit of a pain, two Hitachi hard drives look like they have died, our beloved A8N32 seems to be no more and a bit of bad luck.

The good news is we have now got another Hitachi drive, three more GeForce 7950 and a brand new DFI Expert motherboard which would not have been made possible without the help of some local suppliers. We will go into more detail on the system in a few pages, though. In the mean time, let's have a look at exactly what we are dealing with this time around and if nVidia has delivered a new graphics card which is worth considering!

What went wrong? Ranting!

Since we seemed to be having trouble with Quad SLI (two GeForce 7950GX2 cards) working we grabbed a pair of 7950GX2 stock clocked Leadtek cards locally. Since these were card only (no package) and we did only have them for a few hours, we didn't get any further than having a look at performance when compared to our overclocked XXX XFX graphics card sample.

The main problem we had is the drivers had "QUAD SLI" ticked which made us think we were good to go. We then turned on the load balancing graph which shows you how much load is being put on the card (or core) and at the moment because its only halves the screen, which is the same as when you're running two regular cards in SLI, we aren't entirely sure. If we didn't have a logo saying "QUAD SLI" in the top left corner we might not have been so concerned about the results we were getting. This was about 200 - 300 marks extra in 3DMark when running at 2560 x 1600 and we think with our AMD Athlon FX-60 this is NOT a CPU limitation, as you will be able to see the performance of the overclocked XFX card and the stock Leadtek card, in just a few pages.

Now while we didn't get a chance to have a look at the Leadtek boxes, the company we got them from assured us that "QUAD SLI" was printed on the front of the box. XFX doesn't have Quad SLI on their retail box.

So, while we could have knocked over most the testing in two long days, we spent five long days trying to get Quad SLI working all because nVidia didn't feel like marking their drivers better. There where a few things that led us to believe that Quad SLI wasn't working by the fifth day. The most obvious was the fact that the performance difference was nothing and the other thing that stood out was the fact that the card in the slot furthest away from the CPU didn't seem to generate as much heat. The other problem is the nVidia drivers don't give us a read out for four GPUs under the temperature monitoring area.

The worst thing about it all, we really do feel for a lot of people, because not everyone reads reviews. So what happens when you walk into your local computer store and go say, "I want the best VGA setup" - that computer store bases their judgment off price tag says to the uneducated consumer, "Oh this is what you want, the 7950GX2 which enables Quad SLI." The end-user takes his advice and purchases it, goes home sets it up and think it's kicking butt. The problem is the buyer doesn't know that two cards are just sitting in their slots generating extra heat, placing more strain on the power supply and increasing his electricity bill.

With that rant out the way, the good news is that it looks like Quad SLI is going to be seen soon as nVidia improve their driver support. With this said though, it looks like this was heard from one website that another website mentioned etc etc and may be nothing more then a game of Chinese whispers. We have our fingers crossed it isn't but if the GX2 results we saw from our Gigabyte 7900GX2 review are anything to go by, at the moment, the only real game to see performance increases is F.E.A.R. While we are on the subject of F.E.A.R. we did see a performance increase in our testing today, like many other websites. When we saw we say a performance increase of 200 - 300 marks in the 3DMark series, we're talking a few % but when moving to F.E.A.R. we saw increases of 20%. This makes the whole situation even worse to decipher though - is Quad SLI working but it is not yet optimized properly? The drivers say Quad SLI, the load balancing say Quad SLI and the F.E.A.R. results say the next set of cards are doing something.

Maybe Quad SLI does work and it's no good or maybe there really is just an issue that a new revision driver will fix with optimization - we think the latter. There is no doubt we will know in the next few weeks but we wish we knew now to provide you with an accurate conclusion about the GeForce 7950GX2.

Upon conclusion of this little rant, we can say that there must be some form of Quad SLI doing something for F.E.A.R. to see a performance increase of roughly 20%. The biggest impact that Quad SLI has given us is a lot less sleep over the past week. Something we don't want our readers to experience.

With that out the way, let's move onto the XFX 7950GX2 in more detail before we have a look at the results.

The Package

Like the top of the range XFX cards we have the big box with one mean looking character on the front. We can clearly see that we have a 7950GX2 along with the fact that it is a XXX version clocked at a menacing 570MHz over the default nVidia reference design speed of 500MHz.

The front of the box also shows us that included in the package is Tomb Raider: Legend, which is the latest installment to the Tomb Raider series. It is also worth noting that the XFX offerings are HDCP compliant which is the new video protection method being used for Windows Vista. If you're not looking at upgrading till after Vista is released, this is an important feature.

We also for the first time see a nice big bold "1GB DDR" message printed on the front of the box which is made possible by the two cards combining 512MB DDR3 memory together. In Quad SLI, this (would) offer us a draw dropping 2GB of DDR3 memory.

Turning the box around we have a picture of part of the card, normally there would be a window where the shot is but this time around XFX have simply placed a picture of the card on the back. We can also see a number of features that are present in the 7950GX2.

Opening up the box and diving inside we have got a few cables. We have our HDTV/TV Out connector, S-Video cable so you can make use of TV-Out straight away and a two Molex to 6-pin PCI Express connectors.

Moving to the paperwork side of things we have a quick install guide, manual, TV-Out explanation and a small product catalogue of other products that are available from XFX.

As we mentioned in the first paragraph on the front of the box we can see that Tomb Raider: Legend came with the card along with our normal driver CD. We recommend that you download the latest drivers available once you get the card(s) up and running as they almost always offer some type of performance increase.

From 7900GX2 to 7950GX2

We had a look at the 7900GX2 last month which was just an introduction to Quad SLI, reserved only for the use of system builders such as Dell. There were a few flaws with the 7900GX2 - the placement of the connector between the cards reduced airflow, they were way too long and performance for Quad SLI just wasn't 100% there - hence the reason this product was not set loose in the retail market.

Now most of the issues have been fixed. For starters, in the picture below, you can see three cards - the 7800GTX from BFG, the 7950GX2 from XFX and the 7900GX2 from Gigabyte (in that order). You can clearly see that the 7950GX2 has been shaved down to come in at a total length of 9 inches, only a little longer than the GeForce 7800GTX. This is much more case friendly considering Gigabyte had to hack even their Aurora case to get the original 7900GX2 into the system.

The connection between the two cards is the same as the previous GX2 cards from Gigabyte although the placement is much better.

We can see though in the below image that it goes straight and doesn't block any air from escaping the system. These cards get hot, there is no doubt about that - the way the connector has been placed on the 7950GX2 is fantastic.

We also find that the SLI connection between two cards for Quad SLI has changed. nVidia has opted for one connector between the sets of cards compared to an SLI connector found on each card like we saw with the older 7900GX2 series.

Lastly one of the other main differences is that we find there is only a single 6-pin PCI Express power connector unlike the old 7900GX2 which required two.

Physically there have been a few changes which make the 7950GX2 a much more feasible Quad SLI solution. Between the length shortening, the reduction of power connectors and the better placement of the internal SLI connector, the 7950GX2 is a much more end-user friendly product.

XFX's GeForce 7950GX2 XXX

As we have already mentioned the card length comes in at a reasonable 9 inches. From a top down view, the cards really don't look all that different from a normal high-end graphics bar the small cooler.

We have a single PCI Express power connector in the normal top right position of the card and the normal array of circuitry all over the board. The top card does have the two DVI ports and S-Video port for HDTV out and what not.

What's interesting about the cards of such a high caliber is the small amount of cooling used - the heatsink included is quite large but thin with a small fan. You would think that because of the G71 core being utilized, it would need better cooling, or at least a copper heatsink. The good news is that it looks like there is a water block out there that will fit between the two cards.

The small cooler is made possible since the GeForce 7950GX2 actually has slower clock speeds than the GeForce 7900GTX which uses the same core revision GPU.

Overall the design is so much better then the previous model and while we would recommend a board like the ASUS A8N-SLI Premium, ASUS A8N32-SLI Premium or DFI Lanparty UT SLI DR Expert for a Quad SLI setup, thanks to the increased room between the PCI Express slots you don't actually need them.

And since the GeForce 7950GX2 is technology not SLI, you can run the graphics card on a lot of motherboards (around 40 have been confirmed, so far) with a single PCI Express graphics slot such as Intel 955x and 975x chipset based motherboards giving this SLI-like graphics card more freedom to use on a larger random of boards, and cheaper ones at that. For a complete list of compatible motherboards, download the "NVIDIA GeForce 7950 GX2 - Motherboard Compatibility" PDF which we uploaded to our server, here

Clock Speeds and Setup

Clock Speeds

We haven't seen much from XFX before but they are one company that loves sending out heavily overclocked sample products. XFX has launched the GeForce 7950GX2 with three models - a stock clocked one which comes in at 500MHz on the core and 1200MHz DDR or the memory.

Moving up in the ranks come more interesting models such as the Extreme model which has the core speed bumped up 20MHz (520MHz) and 100MHz bumped up on the memory to give us 1300MHz DDR.

While the small bump in the core speed wasn't much to get excited about the 100MHz memory increase is nice. XFX has not stopped there, the XXX version which we have in our hot little hands weights in at 570MHz core clock which is over a 10% increase and the memory has been bumped up to a massive 1550MHz DDR which is a massive 350MHz over stock and nothing to sneeze at.

Connecting the Beasts

Connecting a total of four cards (2 x 7950GX2) together for Quad SLI apart from being done purely for looks at the moment, *rolls eyes at nVidia*, is done with a single SLI bridge. This is good news as it's the motherboard that comes with the SLI bridge and not the graphics cards. So if you have an SLI motherboard you will be able to put two GeForce 7950GX2 cards in Quad SLI with out having to worry about finding another SLI bridge.

Internal connection between the cards is done by one simple connector in a very well placed position as we saw on the previous pages.

With the cards split a part we did have a quick look and as you can see there is no fancy sticker on the cooler and it does look kind of funny without any VGA or DVI ports on it.

Benchmarks - Test System Setup

Test System Setup

Processor(s): AMD Athlon FX-60 (Supplied by Gigabyte and not AMD)
Motherboard(s): DFI Lanparty UT SLI DR Expert (Supplied by Bronet)
Memory: 2 X 1GB G.Skill ZX PC3200 2-3-2-5 (Supplied by Bronet)
Hard Disk(s): Hitachi 80GB 7,200 RPM SATA 2
Operating System: Windows XP Professional SP2
Drivers: nVidia ForceWare 91.29 and DX9c

Our test system started out a lot different with it running an ASUS A8N32-SLI Premium and X2-3800+. With the issues we were having as mentioned on page 2, we did a fair bit of chopping and changing (we changed every part in the system at least once) and finally ended up with a rock solid stable system as described in our test system section above.

Normally we test at two resolutions, 1024 x 768 and 1600 x 1200. The first is for people who run a standard computer without a massive computer screen, huge amounts of RAM or an expensive processor. It gives them an idea of where they will sit. On the other hand, the latter gives the higher end user an idea of where they should be sitting. If you're running 1280 x 1024 which is what the average 17" LCD users, it's obvious that you should be sitting smack bang in the middle.

While we would have loved to have got away with only those two resolutions, the GX2 is for serious gamers. You're not buying these cards if you can only run at 1024 x 768, hence the reason why our benchmarking begins at 1600 x 1200.

From 1600 we start cranking it up - 1920 x 1200 is there for those lucky 24" LCD owners. We then go even further to those even luckier people with 30" LCDs and test at 2560 x 1600.

While initial setup was a complete pain, we wouldn't put that solely down to the graphics cards and because the whole Quad SLI thing didn't work for us, XFX aren't to blame - overall the whole setup (once up and running) was extremely bug-free.

When it comes to comparing, there was no better option than the Palit 7900GT Sonic in 512MB form. Since the 7950GX2 is almost especially a pair of 512MB 7900GT cards, this made the most sense to us. Also since we thought that at one stage the XFX 7950GX2 was the problem, we grabbed a pair of Leadtek 7950GX2 cards which are stock clocked to provide us with further comparison.

Benchmarks - 3DMark05


Version and / or Patch Used: Build 120
Developer Homepage: http://www.futuremark.com
Product Homepage: http://www.futuremark.com/products/3dmark05/
Buy It Here

3DMark05 is the latest version in the popular 3DMark "Gamers Benchmark" series. It includes a complete set of DX9 benchmarks which tests Shader Model 2.0 and higher.

For more information on the 3DMark05 benchmark, we recommend you read our preview here.

We can see that the SLI 7900GT combination is slightly faster then the Leadtek 7950GX2 but slower then the overclocked XFX 7950GX2 XXX.

Benchmarks - 3DMark06


Version and / or Patch Used: Build 102
Developer Homepage: http://www.futuremark.com
Product Homepage: http://www.futuremark.com/products/3dmark06/
Buy It Here

3DMark06 is the very latest version of the "Gamers Benchmark" from FutureMark. The newest version of 3DMark expands on the tests in 3DMark05 by adding graphical effects using Shader Model 3.0 and HDR (High Dynamic Range lighting) which will push even the best DX9 graphics cards to the extremes.

3DMark06 also focuses on not just the GPU but the CPU using the AGEIA PhysX software physics library to effectively test single and Dual Core processors.

3DMark06 paints a very similar picture, the 7950GX2 XXX from XFX has a really good jump on the stock clocked Leadtek card but not such a huge difference between it and the 7900GT SLI combination provided by the 512MB Sonic Palit cards.

Benchmarks - Half Life 2: Lost Coast HDR

Half Life 2: Lost Coast HDR

Version and / or Patch Used: Unpatched
Timedemo or Level Used: Custom Time demo
Developer Homepage: http://www.valvesoftware.com
Product Homepage: http://www.half-life2.com
Buy It Here

By taking the suspense, challenge and visceral charge of the original, and adding startling new realism, responsiveness and new HDR technology, Half-Life 2 Lost Coast opens the door to a world where the player's presence affects everything around him, from the physical environment to the behaviors even the emotions of both friends and enemies.

We benchmark Half Life 2: Lost Coast (with HDR effects enabled) with our own custom timedemos as to avoid possible driver optimizations using the "record demo_name" command and loading the timedemo with the "timedemo demo_name" command - For a full list of the commands, click here.

In to our first real-world benchmark we can see the same as our synthetic tests. The SLI combination and the XFX 7950GX2 XXX are very close with the XXX again winning and the stock clocked Leadtek lagging back a fair bit.

Benchmarks - F.E.A.R.


Version and / or Patch Used: Unpatched
Timedemo or Level Used: Custom Timedemo
Developer Homepage: http://www.vugames.com
Product Homepage: http://www.whatisfear.com/us/
Buy It Here

F.E.A.R. (First Encounter Assault Recon) is an intense combat experience with rich atmosphere and a deeply intense paranormal storyline presented entirely in first person. Be the hero in your own spine-tingling epic of action, tension, and terror...and discover the true meaning of F.E.A.R.

Unfortunately it still doesn't matter what card you have. You're not going to be playing F.E.A.R. at 2560 x 1600.

The trend is continuing with the XXX XFX 7950GX2 clearly ahead of the stock clocked Leadtek offering but only just ahead of the 7900GT 512MB Palit cards.

Benchmarks - Doom 3

Doom 3

Version and / or Patch Used: Unpatched
Timedemo or Level Used: Custom Time demo
Developer Homepage: http://www.idsoftware.com
Product Homepage: http://www.doom3.com
Buy It Here

Doom 3 is the latest game to hit our test lab and is one of the most intensive games to dates. With our own custom time demo we are able to give a realistic rating on what kind of FPS you will be achieving.

For more information on benchmarking Doom 3 we recommend you check out our extensive article regarding it here.

Doom 3 sees CPU limitations at both 1600 x 1200 and 1920 x 1200, only when we move to 2560 x 1600 does the results change but we can clearly see that all three cards score very close together.

Benchmarks - Quake 4

Quake 4

Version and / or Patch Used: Unpatched
Timedemo or Level Used: Custom Timedemo
Developer Homepage: http://www.idsoftware.com
Product Homepage: http://www.quake4game.com
Buy It Here

Quake 4 is one of the latest new games to be added to our benchmark suite. It is based off the popular Doom 3 engine and as a result uses many of the features seen in Doom. However, Quake 4 graphics are more intensive than Doom 3 and should put more strain on different parts of the system.

Quake 4 again up to 1920 x 1200 sees CPU limitations. It isn't till 2560 x 1600 that the results show what we expected with the cards sitting from fastest to slowest XFX 7950GX2 XXX, Palit 512MB Sonic SLI and Leadtek 7950GX2.

Benchmarks - High Quality AA and AF

High Quality AA and AF

When testing without AA and AD turned on, we saw that Quake 4 and Doom 3 both saw some CPU limitation issues at 1600 x 1200 and 1920 x 1200.

While we didn't think this would be an issue when we started turning on AA and AF, we thought we may as well stress the cards to the maximum. We tested with AA at 8, AF at 16 and at 2560 x 1600. This, our fellow readers, is how games should be played - in "HD" as nVidia have been calling it this week at Computex 2006 trade show.

The XFX 7950GX2 XXX offering is clearly ahead of the Leadtek and Palit setup when we turn on AA and AF.

Since nVidia are unable to do AA and HDR at the same time you only get a SM2.0 score. This shows us that the Palit combination is back up to where it was in previous tests scoring closely to the XFX XXX offering.

Real world gaming at 2560 x 1600 with AA and AF on just isn't really ready at the moment. While the scores show us what we have seen throughout the whole review, you can clearly see why nVidia are offering Quad SLI. Some say there is no use for it and it's a waste of money but we can see that more frames need to be pushed here for a real "High Definition" gaming experience.

With HDR switched off and AA and AF on we can see we get what some people would consider playable and others would consider not so playable. 2560 x 1600 with heavy AA and AF on really does put a lot of pressure on the system and this can clearly be seen here. Bring on Quad SLI, nVidia!

Final Thoughts

After a week of so much pain and so little sleep, you think that you would be left with a bad taste in your mouth but we're left quite pleased with the latest graphics card offering from nVidia and XFX.

Even at 2560 x 1600 with a dual core CPU setup with AA and AF turned on to high levels, we are able to play games. Some people may feel that it even looks pretty good at these settings without AA and AF but once you turn the AA to 8 and the AF to 16, your jaw real does drop as you see your 30" LCD screen light up like it never has before. The problem is that the performance just isn't available without some serious CPU overclocking. The thing is though, there are plenty of people out there who don't want to overclock and this is obvious with companies like XFX making these XXX versions which are apparently selling absolutely crazy.

It is not till our final page of benchmarks where we finally sit back and think... "Boy, there is actually a use for Quad SLI - I really couldn't play Doom 3 at 40FPS." Let's hope that Quad SLI initially sees an increase of around 60% for which case we are then looking at an average frame rate of 64FPS, which is a huge difference and now we are in playable territory.

Games are only getting more intensive as well so there is no doubt that Quad SLI is going to be useful but we have to ask ourselves something. Are games going to make use of this card and technology before the next batch of ATI and nVidia cards come out? Time will only tell.

Exactly what we want to see now is a driver for Quad SLI, more games to make use of the AGEIA PhysX games and more companies producing 30" LCDs which offer a 2560 x 1600 native resolution to help drive price down thus making it a more affordable option. We probably would not recommend Quad SLI to someone who was using a monitor that offered 1920 x 1200 or below.

XFX have done a fantastic job with this card and it is clear that the performance increase it offers over the Leadtek is quite good. It also makes the 7950GX2 a better option over an SLI combination especially considering you have a wider range of other non-SLI motherboards to choose from when looking for a compatible product for your new graphics card.

The real question is what to buy and that is simple - what monitor do you have? If your monitor's maximum resolution is 1600 x 1200, you have two options: Buy the 7950GX2 XXX without even considering purchasing another in the future for Quad SLI or buy two GeForce 7900GT 512MB cards and put them into SLI.

If your monitor's maximum resolution is 1920 x 1200 get a 7950GX2 XXX with the thought of buying one in the near future so you can bump your AA more again and really experience what people are calling "HD Gaming".

If your monitor's maximum resolution is 2560 x 1600 get a 7950GX2 XXX now and start saving those dollars for a second one for when the proper Quad SLI driver follows in the following weeks. For you 30" users with plenty of money to spend, SLI was so yesterday... Quad SLI is what you want!

- Pros
Quad SLI (four GPU) is coming soon for true HD Gaming!
XXX is fXXXing fast even when at high resolutions
Greatly improved over 7900GX2 design, ready for end-user consumption
Available now
Good pricing
Full version game included

- Cons
Quad SLI not ready yet - quickly please, nVidia!
Quad SLI labeling on certain partner cards may confuse buyers (not XFX drawback)
Make sure your wallet is stacked with cash

Rating - 9 out of 10 and TweakTown's "MUST HAVE" Best Performance Award

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Shawn takes care of all of our video card reviews. From 2009, Shawn is also taking care of our memory reviews, and from May 2011, Shawn also takes care of our CPU, chipset and motherboard reviews. As of December 2011, Shawn is based out of Taipei, Taiwan.

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