Performance Predictions for 2600XT?

I'm just wondering how people think this card will perform... looks like the 128-bit memory bus is going to be the major bottleneck on this thing shipping with 120 stream processors, 800MHz core, GDDR4 and up to 512MB of VRAM

On the other hand, it could still be pretty fast...

How do you guys think it will compare with DX9 performance of cards like X1950XT?

It will be slower than the X1950XT. If anything I'd think it would be closer to a X1800XL card. I don't know about the Pro's, GT's or what ever there is thats still in the upper catagory.

deathman20 said:

It will be slower than the X1950XT. If anything I'd think it would be closer to a X1800XL card. I don't know about the Pro's, GT's or what ever there is thats still in the upper catagory.

Click to expand...

I concur. In the best case scenario, it should be as fast as the 8600gts, and that's not faster than a x1950pro, let alone the xt.


dan

Wow... I would think that with 120 stream processors (compared with the 8800GTS's 96) it would perform decently... Think its mainly that 128-bit bus that will hold it back?

No point having that many stream processors with such a small bus is there? I don't know the technicalities but it seems like it would bottleneck itself.

Caviman2201 said:

Wow... I would think that with 120 stream processors (compared with the 8800GTS's 96) it would perform decently... Think its mainly that 128-bit bus that will hold it back?

Click to expand...

Well take note that that it has 120 steam processors doesn't mean it really has that many units. Its like the R600 that means there 5 steam processors per unit. So it only has a 24 units while sure if it can fill each of the 5 steam processors in each 24 unit it will be fast but still lacking. Remember the texture units also are decreased on the 2600 as well.

Caviman2201 said:

Wow... I would think that with 120 stream processors (compared with the 8800GTS's 96) it would perform decently... Think its mainly that 128-bit bus that will hold it back?

Click to expand...

The design of how the R6xx series has set up its shaders makes the effeciant use all of its shaders at any one time nearly impossible. In addition to that their shader speed is significantally slower than that of nVidia (R600 = 700mhz vs 88GTX @ 1.35ghz).

Based on what I see with the R600, the X2600XT will wind up being faster than the 8600GTS but not by a whole lot. It certinaly will be no where near the levels of X1900s at higher resolutions. As deathman said, it *might* be as fast as an X1800XL. I personally think it will be well below that mark, more like in the X1800GTO range but only at 1284/1076 and under, any higher and the memory birate will cause it to come to a screetching halt.

I think ATI should have gone with a 256b bus, and at least tried to muscle NV in the midrange. Not only have they given up the speed crown, but losing in the midrange sector will really hurt. I was hoping the 2600 would trounce the NV equivilant, but not all our wishes come true. So much for a stellar round from ATI this time. Lets see if they can learn from these mistakes and do a quick refresh.

Sentential said:

The design of how the R6xx series has set up its shaders makes the effeciant use all of its shaders at any one time nearly impossible. In addition to that their shader speed is significantally slower than that of nVidia (R600 = 700mhz vs 88GTX @ 1.5ghz).

320 x 700 = 224,000
196 x 1500 = 294,000

^^ and that assumes their shader effeciency is equal to one another which it is not. (nVidia being more efficient)


Based on what I see with the R600, the X2600XT will wind up being faster than the 8600GTS but not by a whole lot. It certinaly will be no where near the levels of X1900s at higher resolutions. As deathman said, it *might* be as fast as an X1800XL. I personally think it will be well below that mark, more like in the X1800GTO range but only at 1284/1076 and under, any higher and the memory birate will cause it to come to a screetching halt.

Click to expand...

2900XT: 743 x 320 = 237760
8800GTX: 1500 x 128 = 192000
8800GTS: 1500 x 96 = 144000
2600XT: 800 x 120 = 96000

Thats if the shaders are at 1500 on the GTX and GTS cards which it isn't at stock if not mistaken.

I have a 320M GTS on its way that I got on trade for a DS3 MB and my 7900GTO. Looks like I got a decent deal by the benches I see so far, I gained about 25-30% The GTS really seems like NV's upper mid range and if the priced come down it will severely hurt ATI.

deathman20 said:

2900XT: 743 x 320 = 237760
8800GTX: 1350 x 128 = 172,800
8800GTS: 1200 x 96 = 115,200
2600XT: 800 x 120 = 96,000
8600GTS: 1450 x 32 = 46,400
8500GT: 900 x 16 = 14,400

Thats if the shaders are at 1500 on the GTX and GTS cards which it isn't at stock if not mistaken.

Click to expand...

Yea my initial numbers are off its difficult to figure out what the shader speed is (default) on the 8800s since they vary so much from brand to brand. I corrected the nvidia ones in my quote of you.

***Be Aware****
______________________

I am Using Sapphire X2600XT rumored specs:

- RV630XT
- GPU Speed: 800MHz
- Memeory Speed: 1400MHz
- Memory Typeı: 256/512MB GDDR3
- Memory Interface: 128-bit
- Connectors: DVI-I + DVI-I + VIVO
- Dual Link DVI: Yes, 2x
- HDCP: Yes
- Integrated Audio Chip: Yes for HDMI
- Windows Vista Premium
__________________________________

Peformance Estimate(s):

8800GTX: Shader (172,800) X 575 ) + (384 x 1800)
=100051200

2900XT: Shader (237,760) X 743 ) + (512 x 1650)
=177500480

2600XT: Shader (96,000) X 800) + (1400 x 128)
=76979200

76979200 / 177500480 = .43368 (43.368% of R600 Estimated)

8600GTS: Shader (46,400) x 675) + (128 x 2000)
=31576000

31576000 / 100051200 = .31559 (31.559% Of G80 Estimated)

Using:
http://www.xtremesystems.org/forums/showpost.php?p=2188702&postcount=73
______________

3DMark 2006 @ Windows XP @ 8.37 driver :


X2900XT default + E6400 2mb cache @ DEFAULT>> 11555 marks


X2900XT default + E6600 4mb cache @ 3600mhz >>> 12530 marks

Click to expand...

(12530 X .43368) = 5,434 3d06 Marks



3dmark06 Estimate(s):
E6400 Default From Link Above:

HD 2900XT: 12530
8800GTX: 11,600


**Estimated 3dmark06 Based On Rounding** 8600GTS: 3,661
**Estimated 3dmark06 Based On Rounding** HD 2600XT: 5,434

Actual Peformance Based on Reviews:
8600GTS: 5,728

Interpolating:
(5,728 - 3,661) = 2067 + 5,434


Final Estimated 3dmark06 HD 2600XT: 7,501

_______________________

So yea... looks like it will be faster than the 8600GTS, thank god too. A 7k 3dmark also puts it soundly in X1800 / X1900 territory for peformance, it definatly has a shot at being a very very nice card.

Lets hope thats correct. Not that I will be upgrading for a while, but the prices of these cards get way out of hand when one massively dominates the other. Look how well we have been doing on CPU's and thats just Intel countering the thought of Barcelona.

X2900XT default + E6400 2mb cache @ DEFAULT>> 11555 marks
That number is way off.

10436 / 11059

First number is 3.0Ghz the second is with a 850/1000 clock on the GPU itself. CPU at 3.6Ghz with default clocks does roughly 11100 marks and OCed to 900/1000 its 12255 marks.

But I get what your saying If its in that range it should out do X1900XT's and even XTX's at stock roughly.
http://www.ocforums.com/showthread.php?t=511746

How well does GDDR4 tend to overclock? I remember there being some issues with with X1950XTX because ATItool wouldn't push the memory as far as it could go.