NVIDIA's First 55nm GPU: GeForce 9800 GTX+ Previewby Anand Lal Shimpi & Derek Wilson on June 24, 2008 12:00 AM EST
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A very smart man at Intel once told me that when designing a microprocessor you can either build a new architecture, or move to a smaller manufacturing process, but you don't do both at the same time. The reason you don't do both is because it significantly complicates the design, validation and manufacturing processes - you want to instead limit the number of variables you're changing in order to guarantee a quick ramp up and good yields of your silicon.
NVIDIA followed this rule of thumb with the GT200, building its "brand new" (or at least significantly evolved) architecture on a tried-and-true 65nm process instead of starting at 55nm. Despite AMD building both RV670 and the new RV770 GPU on TSMC's 55nm process, NVIDIA hadn't built anything on a smaller than 65nm process, including the 1.4 billion transistor GT200.
Shortly after the GT200 launched, AMD "responded" with its Radeon HD 4850, a cheap card by comparison, but a far more interesting one from a practical performance standpoint. Priced at $199 and selling for as little as $170, the Radeon HD 4850 managed to invalidate most of NVIDIA's product line. In response, NVIDIA dropped the price of its GeForce 9800 GTX to $199 as well and introduced one more card: a $229 GeForce 9800 GTX+.
Originally we thought the GTX+ was a silly last minute afterthought as it looked like nothing more than an overclocked 9800 GTX. While its clock speeds are higher, it also happens to be the very first 55nm NVIDIA GPU. The specs are as follows:
|9800 GTX+||9800 GTX|
|Texture Address / Filtering||64 / 64||64 / 64|
|Memory Bus Width||256-bit||256-bit|
|Manufacturing Process||TSMC 55nm||TSMC 65nm|
The core clock went up 9.3%, shader clock went up 8.6% and memory clock stayed the same. The clock speed bumps are marginal and by far the more interesting aspect of the chip is how much less power it consumes thanks to its 55nm process, which thanks to AMD should be quite mature by now.
Here's the full NVIDIA lineup:
|GTX 280||GTX 260||9800 GX2||9800 GTX+||9800 GTX||8800 GTS 512||8800 GT|
|Texture Address / Filtering||80 / 80||64 / 64||128 / 128||64 / 64||64 / 64||56 / 56||56 / 56|
|Memory Bus Width||512-bit||448-bit||256-bit x 2||256-bit||256-bit||256-bit||256-bit|
|Manufacturing Process||TSMC 65nm||TSMC 65nm||TSMC 65nm||TSMC 55nm||TSMC 65nm||TSMC 65nm||TSMC 65nm|
|Price Point||$650||$400||$500||$229||$199||$280||$170 - $230|
Notice something very wrong? The 8800 GTS 512 and 8800 GT both need to drop in price significantly, they are simply uncompetitive at their current price points. I expect one of those two products to go the way of the dodo but it's unclear which one; the 8800 GT is cheaper to make, but perhaps it's easier to produce 65nm parts with 128 SPs so the GTS 512 could stick around at a lower price point as well.
The GeForce 9800 GTX+ will be available starting July 16th.