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Review: BFG NVIDIA GeForce 9800 GTX. Got £200 for a graphics card? Read this

by Tarinder Sandhu on 1 April 2008, 14:01

Tags: BFG GeForce 9800 GTX+ OC, NVIDIA (NASDAQ:NVDA), BFG Technologies

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Another 9-series card. What's new this time, huh?

Trotting out our familiar table.

Graphics cards NVIDIA GeForce 9800 GX2 1024 NVIDIA GeForce 9800 GTX 512 NVIDIA GeForce 8800 GT 512 NVIDIA GeForce 8800 GTS 512 NVIDIA GeForce 8800 Ultra 768 ATI Radeon HD 3870 X2 1024 ATI Radeon HD 3870 512
PCIe PCIe 2.0 PCIe 1.x PCIe 2.0
GPU clock 600MHz 675MHz 600MHz 650MHz 612MHz 825MHz 775MHz
Shader clock 1,500MHz 1,688MHz 1,500MHz 1,625MHz 1,500MHz 825MHz 775MHz
Memory clock (effective) 2,000MHz 2,200MHz 1,800MHz 1,940MHz 2,160MHz 1,802MHz 2,250MHz
Memory interface, size, and implementation 2x 256-bit, 1,024MiB, GDDR3 256-bit, 512MiB, GDDR3 384-bit, 768MiB, GDDR3 2x 256-bit, 1,024MiB, GDDR3 256-bit, 512MiB, GDDR4
Memory bandwidth 128GB/sec (card) 70.40GB/sec 57.60GB/sec 62.1GB/sec 103.68GB/sec 115.328GB/sec (card) 72.8GB/sec
Manufacturing process TSMC, 65nm TSMC, 90nm TSMC, 55nm
Transistor count 1,508M 754M 681M 1,300M 666M
Die size 2x 296mm² 296mm² 484mm² 2x 192mm² 192mm²
DirectX Shader Model 4.0 4.1
Vertex, fragment, geometry shading (shared) 256 FP32 scalar ALUs, MADD dual-issue (unified) 128 FP32 scalar ALUs, MADD dual-issue (unified) 112 FP32 scalar ALUs, MADD dual-issue (unified) 128 FP32 scalar ALUs, MADD dual-issue (unified) 640 FP32 scalar ALUs, MADD dual-issue (unified) 320 FP32 scalar ALUs, MADD dual-issue (unified)
Peak GFLOP/s 768 432 336 416 384 1,056 496
Data sampling and filtering 128ppc address and 128ppc bilinear INT8 filtering, max 16xAF 64ppc address and 64ppc bilinear INT8 filtering, max 16xAF 56ppc address and 56ppc bilinear INT8 filtering, max 16xAF 64ppc address and 64ppc bilinear INT8 filtering, max 16xAF 32ppc address and 64ppc bilinear INT8 filtering, max 16xAF 16ppc address and 32ppc bilinear INT8 filtering, max 16xAF
Peak GTexel/s (bilinear) 76.8 43.2 33.6 41.6 19.584 26.4 12.4
ROPs 32 16 16 16 24 32 16
Peak TDP (claimed) 196 156 105 140 175 196 110
Multi-GPU SLI - two-board SLI - three-board SLI - two-board SLI - three-board CrossFire - two-board CrossFire - four-board
Outputs 2 x dual-link DVI w/HDCP, HDMI 2 x dual-link DVI w/HDCP, HDMI (native, on GPU) 2 x dual-link DVI w/HDCP, mini-DIN 2 x dual-link DVI w/HDCP (discrete ASIC), mini-DIN 2 x dual-link DVI (HDMI) w/HDCP, mini-DIN (VIVO)
Hardware-assisted video-decoding engine NVIDIA's PureVideo HD - full H.264 decode and partial VC-1 decode AMD UVD - full H.264 and VC-1 decode
Reference cooler dual-slot dual-slot single-slot dual-slot dual-slot
Retail price (default-clocked model) £389 £220? £139 £179 £399 £249 £129

9-series, really? Sure it's not a GeForce 8800 GTS 512 in disguise?

What's not so new, compared to GeForce 8800 GTS 512

We know that the GeForce 9800 GTX is the formal successor to the long-in-the-tooth GeForce 8800 GTX - the GPU, launched in November 2006, that revolutionised the way that pixels are painted on to your screen.

However, take a close, close look at the vital statistics for the GeForce 9800 GTX and 8800 GTS 512. Both are built on a 65nm manufacturing process; harness 754M transistors; are endowed with 128 stream processors; interface with external memory - 512MiB, typically - via a 256-bit memory bus; and can sample and address the same number of pixels per clock cycle, etc.

[advert]The point here is that the 9800 GTX is, essentially, a faster-clocked version of the 8800 GTS 512 that was launched at the end of November. The core frequency sees a meagre ~4 per cent increase, shaders run at 12.5 per cent faster, and GDDR3 memory is 22 per cent faster.

NVIDIA states that the GPU has integrated HDMI support - just like the GeForce 8800 GT and GTS 512 - offering audio pass-through via the DVI port and through a certified DVI-to-HDMI adaptor, but the user still needs to connect a S/PDIF cable to the card, which isn't as elegant as ATI's approach on its Radeon HD 3000-series cards.

Our previous testing has showed that the 8800 GTS 512 was, on balance, just a little slower than the now-discontinued Ultra. GeForce 9800 GTX should become NVIDIA's fastest single-GPU board and should benchmark around 10 per cent higher than a stock-clocked 'GTS 512.

Initial pricing estimates indicate that stock-clocked cards will sell for $299-$349. Knowing that default-clocked 8800 GTS 512s currently e-tail for around $250 in the US and £180 in the UK, it's safe to assume UK-based pricing of around £230 today, launch day, dropping to £215 in a week or so's time. Incidentally, that's the same price as the current GeForce 8800 GTX 768MiB.

What's kind of new but seen before on other NVIDIA GPUs?

Now, one of the erstwhile 8800 GTX - and, indeed Ultra's - features not available on the G9x-class of GPUs was the ability to run three cards in tandem - three-way SLI - through the provision of two SLI connectors on the cards. The recently-released GeForce 9800 GX2, we noted, shoehorned in two GPUs per board and could run a four-GPU combination by adding another card, but the GeForce 9800 GTX fills the vacuum left by two-connector 8800 GTX well enough.

Also note that, like the GeForce 9800 GX2, the 9800 GTX supports NVIDIA's HybridPower, where, on a compatible chipset that features an IGP, the discrete, wattage-hungry card can be turned off when not in heavy 3D use, saving power and routing video through the IGP instead.

Released with the ForceWare 174.xx drivers and currently software-upgraded on the 9-series cards for now, NVIDIA introduced dynamic contrast and colour enhancements for better-looking images, it says. Further, the driver supports dual-stream decode, which hardware-accelerates the decoding of two video streams running concurrently. There are only few instances where we can see this being useful - picture-in-picture commentary, for example. NVIDIA will debut these incremental increases in PureVideo HD's functionality on 8-series cards at a later date.

Other bits, and summary

NVIDIA recommends a 450W PSU with at least 24A on the 12V rail if running a single card. That recommendation spirals to 750W for two-way SLI and 1,000W for three-way SLI. The card also works in conjunction with NVIDIA ESA (Enthusiast System Architecture) for thermal monitoring and user-defined fan-speed modulation.

The GeForce 9800 GTX 512 is significantly cheaper to produce than the 768MiB-equipped GeForce 8800 GTX that it replaces. The 9800's frame-buffer, then, is smaller, and memory bandwidth suffers when compared to the 384-bit setup on the G80 GTX, but that's somewhat masked by its superior texturing ability. It will lose some bandwidth-intensive gaming benchmarks against the former GTX but win others that rely on furious texturing ability.

With all that in mind, the nomenclature hides the fact that, really, it's just a faster-clocked version of the current GeForce 8800 GTS 512, albeit it with three-way SLI and integrated HDMI support.

Apart from faster speeds and the possibility of three-way SLI, the GeForce 9800 GTX brings nothing really new to bear that we haven't seen before. By rights, then, it should be called the GeForce 8900 GTX, because we're not sure how NVIDIA's pulled the 9-series moniker out of the PR bag. All it will do, really, is potentially confuse buyers into thinking it's a whole generation ahead of the GeForce 8800 GTS 512, which it clearly isn't. We reckon the fact that it supports HybridPower and three-way SLI isn't enough for a generation's gap in nomenclature.

Retail GeForce 9800 GTX pricing is such that it's relatively close to ATI's dual-GPU Radeon HD 3870 X2, which can now be picked up for around £249. Let's now see it if it's faster....