SUMMARY: Today we compare three of the latest nVidia based AGP and PCI Express graphics cards from Gigabyte. We look at the GeForce 6200 for the low-end market, the impressive value for money GeForce 6600GT with SLI support along with the high-end 6800GT AGP which offers great performance but not at the price of the very high-end models. Read on and work out which graphics card is best for your needs as we run them through our usual array of gaming benchmarks!
The NX66T series is Gigabyte’s mid-level graphics card, but one thing is for sure, it’s packaged more like a high-end graphics card. The box is actually one of the biggest I have seen for a graphics card, and when you get the card out, it becomes apparent that the card is aimed at the gamers when you open the box and reveal the contents. First off you have your card, a Driver CD with the V-Tuner II program for overclocking and monitoring, PowerDVD 5 disk, user manual, S-Video/HDTV splitter box and one of the best games I have ever personally played Doom 3 all within the one package.
The card size and layout is that of the nVidia reference design, however, Gigabyte has made a few changes for aesthetics. First off the PCB isn’t the same green one we saw from nVidia’s reference card but a night deep blue, which has been the colour of the nVidia based cards from Gigabyte for a little while now. The heatsink also is quite different, as you can see, the heatsink on the reference cards tend to cover the memory (though most of them don’t cool the memory) Gigabyte has gone with a gold coloured smaller heatsink.
With the heatsink removed we see the core used for the NX66T. The GeForce 6600GT core is the first core from nVidia to be a native PCI Express based graphics core. nVidia’s design up till the release of the 6600 core was to design their GPU’s for the AGP bus type and use a bridge chip in order to translate the AGP signals of the GPU into the PCI Express signals used by the newest Northbridge chipsets.
Due to limits of the AGP bus type, nVidia has now moved over to native PCI Express designs and using the same bridge chip in reverse to convert PCI Express over to AGP signals.
GDDR 3 memory is the latest memory to come out for graphics cards. GDDR 3 memory is designed on the same basis of memory used for system memory; however, latencies and clock speeds are set for graphics cards - 128MB of Samsung 2ns FBGA memory in a 128-bit memory array.
The 6600GT as most know has support for SLI functions, and Gigabyte has included the SLI port on the top of the card. Gigabyte specifies that the SLI function will only work with the exact same cards; however, we haven’t been able to do any tests to see if this is correct or not as yet.
Overclocking Results
For our overclocking tests we used the Coolbits registry command and has been one of the best utilities for overclocking nVidia cards for some time.
With a default clock speed of 600MHz on the on the GPU and 900MHz DDR on the memory, we didn’t know what to expect. We managed (with the stock cooling setup Gigabyte provides) a core clock of 720MHz and a memory clock of 1.14GHz DDR which is a very good overclock result indeed.
