5970 owners I need your help

[Jacky60]

It seems to me 4890 xfire is pretty much as good and just over half the price of a 5970. Has anyone upgraded from 4890 xfire and seen much improvement? Has anyone any benchmarks other than the one below to justify another £250 ($350) for the 5970 apart from the DX11 capability?

http://www.bjorn3d.com/read.php?cID=1736&pageID=8011

I know in theory 5970 should pwn 4890 xfire but this does not seem to be the case.

 

[x3sphere]

It seems to me 4890 xfire is pretty much as good and just over half the price of a 5970. Has anyone upgraded from 4890 xfire and seen much improvement? Has anyone any benchmarks other than the one below to justify another £250 ($350) for the 5970 apart from the DX11 capability?

http://www.bjorn3d.com/read.php?cID=1736&pageID=8011

I know in theory 5970 should pwn 4890 xfire but this does not seem to be the case.

First off, 3DMark isn't a good indicator of a card's real-world performance. Look at the Far Cry 2 benches, the 5970 blows away two 4890s in CrossFire:

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Taking scaling issues into account I would say the 5970 is more or less equal to 3 4890s in trifire, with the added benefit of DX11 capability. I'll also add that the site you linked to, their numbers seem way off. Two 5770 trailing closely behind a 5970? Makes no sense. Here's a better bench from Anandtech:

 

[happy medium]

A gtx 295 is about = to 2 gtx 275's in sli.
2 gtx 275's = 2 4890's
2 4890's should be about = to a gtx295
A gtx 295 is slower then a 5970 by 25%.
The 58xx series scales better then the 48xx series when crossfired.

5970 is the better solution and will get better with better drivers.

 

[cbn]

I know in theory 5970 should pwn 4890 xfire but this does not seem to be the case.

Why would HD5970 pwn 4890s in Crossfire?

1. The clocks on the 5970 are lower.

2. The 4890s have more memory bandwidth right?

 

[NoQuarter]

Why would HD5890 pwn 4890s in Crossfire?

1. The clocks on the 5890 are lower.

2. The 4890s have more memory bandwidth right?

Pretty sure you meant 5970, but it's because the 5970 regardless of underclock still owned the GTX295 that is about equal to 2x4890 on that bench..

The 5870 has double the shader processors than the 4890 (1600 vs 800), a 5970 is double that which means even if it's clocked lower it's still twice 2x4890's (2x1600 vs 2x800). Also the memory on the 5970 is still clocked slightly higher than the 4890 (1000MHz vs 900MHz)

If anything, 2 4890's should be a near equal match for the 5870 which is pretty much what you see when you look at 5870 vs GTX295, and 2 5870's (re: 5970) should stomp 2 4890's no matter the clock.

 

[cbn]

Pretty sure you meant 5970, but it's because the 5970 regardless of underclock still owned the GTX295 that is about equal to 2x4890 on that bench..

The 5870 has double the shader processors than the 4890 (1600 vs 800), a 5970 is double that which means even if it's clocked lower it's still twice 2x4890's (2x1600 vs 2x800). Also the memory on the 5970 is still clocked slightly higher than the 4890 (1000MHz vs 900MHz)

If anything, 2 4890's should be a near equal match for the 5870 which is pretty much what you see when you look at 5870 vs GTX295, and 2 5870's (re: 5970) should stomp 2 4890's no matter the clock.

Sorry, I did mean HD5970 (not HD5890). I just made the correction to the original post (see edit)

Okay, now with that out of the way....

While it is true that HD5970 has twice as mean Stream processors as HD4890 they are clocked lower. This gives two HD4890s more GPU power than a single HD5970.

Furthermore, a single HD5970 may have higher clocked memory but it is still on a single 256 bit bus. Two HD4890s have two 256 bit buses? AFAIK, the memory bus isn't mirrored like the VRAM is. However, I could be wrong.

 

[NoQuarter]

Sorry, I did mean HD5970 (not HD5890). I just made the correction to the original post (see edit)

Okay, now with that out of the way....

While it is true that HD5970 has twice as mean Stream processors as HD4890 they are clocked lower. This gives two HD4890s more GPU power than a single HD5970.

Furthermore, a single HD5970 may have higher clocked memory but it is still on a single 256 bit bus. Two HD4890s have two 256 bit buses? AFAIK, the memory bus isn't mirrored like the VRAM is. However, I could be wrong.

Each GPU on the 5970 has its own memory bus and has its own set of 1GB of ram that are completely separated from each other, all dual GPU cards are like that.

I still fail to see how 5970's 2x1600 @ 725MHz could get less work done than 2 4890's 2x800 @ 850MHz. That's 3200 @ 725MHz vs 1600 @ 850MHz with very similar architecture. The 5970 would have to be clocked at 425 MHz to even start comparing the two.

Again 2 4890's at 1600 @ 850MHz is closest compared to the 5870 at 1600 @ 850 MHz they are very similar in performance. The 5870 is basically 2 4890's packed onto 1 chip and we know the 5970 is faster than the 5870 or it wouldn't exist.

 

[dguy6789]

5970 has a lot more power than 4890 Crossfire. Not even in the same league really.

Radeon HD 5970:
Pixel Fillrate: 46400 MPixels/sec
Texture Fillrate: 116000 MTexels/sec
Memory Bandwidth: 256 GB/sec

Radeon HD 4890 Crossfire:
Pixel Fillrate: 27200 MPixels/sec
Texture Fillrate: 68000 MTexels/sec
Memory Bandwidth: 249.6 GB/sec

The 5970 even has more GPU power than three way 4890 Crossfire.

 

[cbn]

I still fail to see how 5970's 2x1600 @ 725MHz could get less work done than 2 4890's 2x800 @ 850MHz. That's 3200 @ 725MHz vs 1600 @ 850MHz with very similar architecture. The 5970 would have to be clocked at 425 MHz to even start comparing the two.

You are right. HD5970 has twice as many stream processors as HD4890s in Crossfire.

Seriously, I think I was getting HD5970 confused with the 1600 stream processors of HD5870 all the while. HD5970 has 3200 stream processors.

 

[Jacky60]

OK 5970 is vastly and immeasurably superior to 4890 xfire. From a good but often stilted experience to a totally fluid and 8x AA lifelike experience I'm sold- hook, line and sinker! It's like comparing night and day and though the improvement is £250 its so worth it-max settings xcept post processing in Arma 2 its between 30 and 60 fps and never below 30 and unbelievable quality!