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NVIDIA's GeForce GTX 480 finally unleashed. Reviewed and rated.

by Tarinder Sandhu on 26 March 2010, 23:00


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How does GeForce 4x0 line up

Here are GeForce GTX 480 and 470 laid out in table form.

Graphics cards NVIDIA GeForce GTX 480 1,536MB NVIDIA GeForce GTX 470 1,280MB NVIDIA GeForce GTX 295 1,792MB NVIDIA GeForce GTX 285 1,024MB ATI Radeon HD 5970 2,048MB ATI Radeon HD 5870 1,048MB ATI Radeon HD 5850 1,024MB
General clock 700MHz 607MHz 576MHz 648MHz 725MHz 850MHz 725MHz
Shader clock 1,401MHz 1,215MHz 1,242MHz 1,476MHz 725MHz 850MHz 725MHz
Memory clock (effective) 3,696MHz 3,348MHz 1,998MHz 2,484MHz 4,000MHz 4,800MHz 4,000MHz
Memory interface and size 384-bit, 1,536MB GDDR5 320-bit, 1,280MB GDDR5 896-bit (2 x 448-bit), 1,792MB, GDDR3 512-bit, 1,024MB, GDDR3 512-bit (2 x 256-bit), 2,048MB 256-bit, 1,024MB, GDDR5 256-bit, 1,024MB, GDDR5
Memory bandwidth 177.4GB/s 133.9GB/s 2 x 111.9GB/s 159GB/s 2 x 128GB/s 153.6GB/s 128GB/s
Manufacturing process TSMC, 40nm TSMC, 40nm TSMC, 55nm TSMC, 55nm TSMC, 40nm TSMC, 40nm TSMC, 40nm
DirectX/ Shader Model DX11, 5.0 DX11, 5.0 DX10, 4.0 DX10, 4.0 DX11, 5.0 DX11, 5.0 DX11, 5.0
Vertex, fragment, geometry shading (shared) 480 FP32 scalar ALUs, MADD + MUL  448 FP32 scalar ALUs, MADD  + MUL  480 FP32 scalar ALUs, MADD + MUL  240 FP32 scalar ALUs, MADD + MUL  3,200 FP32 scalar ALUs, MADD + MUL 1,600 FP32 scalar ALUs, MADD + MUL  1,440 FP32 scalar ALUs, MADD + MUL 
Single-precision GFLOPS (single-issue) 1,345 1,088 1,192
4,176 2,720
Texturing 60ppc bilinear
30ppc FP16
15ppc FP32
56ppc bilinear
28ppc FP16
14ppc FP32
160ppc bilinear
80ppc FP16
40ppc FP32
80ppc bilinear
40ppc FP16
20ppc FP32
160ppc bilinear
80ppc FP16
40ppc FP32
80ppc bilinear
40ppc FP16
20ppc FP32
72ppc bilinear
36ppc FP16
18ppc FP32
ROPs 48
64 32
GPixels/s throughput 33.6
27.2 23.2
GTexel/s bilinear 42
Board power (max) 250W 215W 289W 183W 294W 188W 170W
Multi-GPU Three-way SLI Three-way SLI Two-way SLI Three-way SLI Two-way XFire Four-way XFire Four-way XFire
Board length 10.5in 9.5in 10.5in 10.5in 12in 11in 9.5in
Connectors (native) 2x dual-link DVI
2x dual-link DVI
2 x dual-link DVI, HDTV-out,HDMI 2x dual-link DVI
2x dual-link DVI
2x dual-link DVI
HDMI, DisplayPort, 
2x dual-link DVI
HDMI, DisplayPort, 
Etail price  £440+ £299+
£550 £310 £225
Analysis: GeForce GTX 480

Most pundits expected GeForce GTX 480 to be composed of 512 cores. NVIDIA is disabling one SM unit (32 cores) and the associated texturing, L1 cache, and PolyMorph engine that goes with it. We don't know exactly why GTX 480 loses out an SM, but the logical reason has to do with ensuring a quality of yield that makes it economically feasible. Will we see a 512-core GTX card? The chances are it will come into being when yields have significantly improved at TSMC, and that kind of timeframe falls in line with the release of the professional part, Tesla.

Clocking in at 700MHz and 1,400MHz for the general and shader clocks, respectively, and knowing the number of texturing units and ROPs, the GeForce GTX 480's peak numbers aren't particularly impressive for a 3bn-transistor chip. The Radeon HD 5870 has a decided advantage in shading and texel filtering, but it gives way on the ROP-led pixel throughput. Twin-GPU Radeon HD 5970 wins every performance segment, we note.

Peak numbers don't take efficiency into account, and this is one factor that NVIDIA is banking upon with GTX 4x0, that is, sustaining high throughput at all times. Looking out from the ROPs to the frame-buffer and NVIDIA's 384-bit bus is fed by 1,536MB of GDDR5 memory that's clocked at a rather lowly 3.7GHz. The upshot is class-leading bandwidth for a single-GPU solution, due to the ample width, but we imagine that NVIDIA will increase the GDDR5 frequency over time.

Put it all together and you realise why NVIDIA has been somewhat conservative with the frequencies. The company has to maintain acceptable yields and thermals. Board power is rated to 250W - 33 per cent higher than the HD 5870 - and increasing frequencies will bring fundamental thermal obstacles to the fore.

Our best-guess pricing indicates that etailers will charge £440 for NVIDIA's finest GPU, probably more on launch day, pushing its price 40 per cent higher than Radeon HD 5870's.

Analysis: GeForce GTX 470

NVIDIA knows that GF100 needs to be distilled into a cheaper GPU from the get-go. GeForce GTX 470 loses an SM unit (32 cores), eight ROPs, and significant frequency for the core, shader, and memory. Back-of-the-envelope notes indicate that it will perform at around 65 per cent of the level of GTX 480, putting it, NVIDIA hopes, around the Radeon HD 5850/5870 in performance terms.

GeForce GTX 470 is still a hot beastie, based around the same 3bn-transistor GPU, and it pulls around 30W more than AMD's flagship single-GPU card, based on company-provided TDPs. It carries the same dual-link DVI and mini-HDMI outputs as the GTX 480; DisplayPort being conspicuous by its absence.

The peak numbers would give the victory, easily, to AMD's range of Radeon 5-series GPUs on a pound-for-pound basis. Benchmarks will show if this is true...