This is the tricky area... but I'll go with how I've always rolled recommending hardware: buy the best graphics card you can. Driving a new VR headset that pumps away at 90/120/144Hz isn't easy, so you'll need to have the graphics card chops to handle that.
Valve recommends a GeForce GTX 1060 or Radeon RX 580, but I seriously do not think that's anywhere near enough to run Half-Life: Alyx on anything less than minimal graphics settings.
1: GeForce RTX 2080 Ti
NVIDIA leads the graphics card pack with its flagship GeForce RTX 2080 Ti graphics card, based on the Turing GPU architectrure and packing 11GB of super-fast GDDR6 memory, it's the best graphics card you can buy as a gamer. Sure, there's the TITAN RTX and its drool-worthy 24GB of GDDR6... but it costs $2499.
The GeForce RTX 2080 Ti will provide you with the best performance possible in Half-Life: Alyx, keeping the frames at above 120-144FPS which is required by the Valve Index. You will need to keep the FPS above 75-90FPS as the other VR headsets in the Oculus Rift/Rift S and HTC Vive/Vive Cosmos headsets all have 75/90/120Hz refresh rates.
There are a few choices here with NVIDIA's flagship GeForce RTX 2080 Ti, where you can get the Founders Edition for $1199 from NVIDIA's own website -- but at the time of writing it wasn't available. The next best 3 options on Amazon include custom models from ASUS, MSI, and EVGA. Any of these would be an amazing graphics card to power Half-Life: Alyx to its fullest -- on the Valve Index headset at 120/144FPS.
- ASUS GeForce RTX 2080 Ti ROG Strix Gaming OC - $1213 (Buy from Amazon)
- MSI GeForce RTX 2080 Ti GAMING X TRIO - $1198 (Buy from Amazon)
- EVGA GeForce RTX 2080 Ti Black Edition Gaming - $1106 (Buy from Amazon)
2: GeForce RTX 2080 SUPER
The second-best Turing-based graphcis card that NVIDIA has on the market is the GeForce RTX 2080 SUPER, which sees a drop in performance and a bigger drop in its framebuffer down from 11GB on the GeForce RTX 2080 Ti to 8GB on the GeForce RTX 2080 SUPER.
It's still a kick ass graphics card for the money, so if you don't have enough cash to splash on the GeForce RTX 2080 Ti, then the GeForce RTX 2080 SUPER is still a mighty fine choice. There are some really great custom GeForce RTX 2080 SUPER graphics cards to choose from, too -- all capable of plowing through Half-Life: Alyx.
NVIDIA sells its own GeForce RTX 2080 SUPER Founders Edition for $699 on its website, but there are a bunch of custom variants that you are better off buying. Hell, EVGA's custom GeForce RTX 2080 SUPER Black Gaming graphics card is also $699 -- with far superior cooling to the Founders Edition.
- ASUS GeForce RTX 2080 SUPER STRIX Gaming Advanced - $769 (Buy from Amazon)
- MSI GeForce RTX 2080 SUPER GAMING X TRIO - $782 (Buy from Amazon)
- EVGA GeForce RTX 2080 SUPER Black Gaming - $699 (Buy from Amazon)
3: GeForce RTX 2070 SUPER
The third option of a graphics card to run Half-Life: Alyx is yet another NVIDIA GeForce RTX card, with the GeForce RTX 2070 SUPER -- which also has 8GB of VRAM. It is a great card if you didn't want to spend the $700+ on a GeForce RTX 2080 SUPER, as you can get the NVIDIA GeForce RTX 2070 SUPER Founders Edition for $499.
There are plenty of custom cards available at over $500, with EVGA offering its GeForce RTX 2070 SUPER Black Gaming graphics card for $513 or so -- while MSI throws up its GeForce RTX 2070 SUPER GAMING X TRIO
- ASUS GeForce RTX 2070 SUPER STRIX Gaming Advanced - $584 (Buy from Amazon)
- MSI GeForce RTX 2070 SUPER GAMING X TRIO - $534 (Buy from Amazon)
- EVGA GeForce RTX 2070 SUPER Black Gaming - $513 (Buy from Amazon)
4: Radeon VII
The fastest Radeon graphics card that AMD has in its current roster is the Radeon VII -- offering up the Vega 20 GPU with 16GB of super-fast HBM2 memory. It's not as fast as NVIDIA's flagship GeForce RTX offerings, but if you wanted the very best Team Red graphics card then this is it -- I would suggest the Radeon RX 5700 XT over this, however.
- XFX Radeon VII - $579 (Buy from Amazon)
5: Radeon RX 5700 XT
AMD had a big turn around when it dropped its Navi GPU architecture into the graphics card game in 2019, with a stellar offering in its flagship Radeon RX 5700 XT graphics card. I wouldn't recommend buying a reference model Radeon RX 5700 XT -- as there are some truly kick ass custom Radeon RX 5700 XT graphics cards that are more worthy of your money for Half-Life: Alyx.