Reviews - NVIDIA GeForce GTX 480 vs. AMD Radeon HD 5850 CrossFire - battle at £450

[ehhhhhhh]

very informative review

I wonder about the occasional performance difference between the 5850CF and 5970. Can it happen because the 5850s run on separate PCIe slots, hence the GPUs can achieve bigger throughput?

my second guess is that it's driver related...


anyway thanks a lot

[shaffaaf27]

super review!

just goes to show how much fail nvidia put out. any reason for them beating a 5970?

[scottismo]

Has anyone seen any info on what sort of power supply you will need to run this sort of configuration? I was thinking of using an 850W Corsair for my own build but I notice in this review they're using the 1000W version. Anyone know if the 850 will do?

I was considering a 5970 but this might just have changed my mind and saved me a few £££'s. As others have said, I too would like to know why they were performing better than the 5970. Presumably two XFX Black Edition cards would be even better still...

[Ramon]

very informative review

I wonder about the occasional performance difference between the 5850CF and 5970. Can it happen because the 5850s run on separate PCIe slots, hence the GPUs can achieve bigger throughput?

my second guess is that it's driver related...


anyway thanks a lot

5970 = 3200sp and 80tu
5850XF = 2880sp and 72tu

CPU speed (725Mhz), RAM speed (1Ghz) and ROPs (32) are the same.

So there's a 11.1% difference of raw processing power between the 2 setup, specifically located on sp and tu. Many test have shown a difference of around 2% when driving a video card at x8 instead of x16. On the other hand, the 5970 do some of inter-GPU communication directly through the on-board PLX PEX 8647 switch commanding 48 PCI-Lanes, avoiding to go out to the motherboard PCIe lanes.

On paper, there is no doubt the 5970 should be faster in all scenarios. Logically, that leaves drivers to be the only culprit.

[shaffaaf27]

would the 5970 have 2x32 rops?

[ehhhhhhh]

Has anyone seen any info on what sort of power supply you will need to run this sort of configuration? I was thinking of using an 850W Corsair for my own build but I notice in this review they're using the 1000W version. Anyone know if the 850 will do?

I was considering a 5970 but this might just have changed my mind and saved me a few £££'s. As others have said, I too would like to know why they were performing better than the 5970. Presumably two XFX Black Edition cards would be even better still...

1000w psu is just bs, you would be fine with a good 600-650w psu...

[Tarinder]

Has anyone seen any info on what sort of power supply you will need to run this sort of configuration? I was thinking of using an 850W Corsair for my own build but I notice in this review they're using the 1000W version. Anyone know if the 850 will do?

I was considering a 5970 but this might just have changed my mind and saved me a few £££'s. As others have said, I too would like to know why they were performing better than the 5970. Presumably two XFX Black Edition cards would be even better still...

Hi,

Corsair has been kind enough to provide us with a number of PSUs. We've previously used the 850W version for two-card CrossFireX, powered by a highly-clocked Intel Core i7 processor. You will have no problem with such a supply should you want to build a decent rig.

[Zak33]

Has anyone seen any info on what sort of power supply you will need to run this sort of configuration? I was thinking of using an 850W Corsair for my own build but I notice in this review they're using the 1000W version. Anyone know if the 850 will do?

http://www.hexus.net/content/item.ph...=24061&page=12

check out the system power draw under masx load

And the use of a 1000W PSU is simply convenience for the labs, because it's there. Obviously is only draws the power it needs, so doesn't use 1000W all the time

[Stukinit]

I feel so happy about my purchase now... Thanks for the review, been lurking for awhile but didn't decide to make an account till I read this. Great review and better findings!

[borandi]

This is a great article Hexus. I'm running a 2x5850 XF setup now anyway

[GheeTsar]

Best article on Fermi vs Cypress yet IMHO. Keep up the good work.

[[-Stash-]]

Good to see that XF scaling is starting catch up with SLI scaling a bit. All I really want now is fr nvidia to re-enable Physx processing in their drivers when you're using an ATI card as your main display card. They'd convince me to buy a 9600GT or even a 250GTS just as a Physx processor, but I wouldn't buy a nvidia card as my main graphics card right now.

[Ramon]

would the 5970 have 2x32 rops?

You are right, I've made a little mistake. Both setup, the 5970 and the 5850XF have 2X32 = 64 ROPs.


So I should have written:

5970 = 3200sp and 80tu
5850XF = 2880sp and 72tu

CPU speed (725Mhz), RAM speed (1Ghz) and ROPs (2X32=64) are the same.

The conclusion remains: Drivers must be the issue to explain why the 5850XF is as fast as the 5970 in many benchmark.

[Ramon]

Good to see that XF scaling is starting catch up with SLI scaling a bit. All I really want now is fr nvidia to re-enable Physx processing in their drivers when you're using an ATI card as your main display card. They'd convince me to buy a 9600GT or even a 250GTS just as a Physx processor, but I wouldn't buy a nvidia card as my main graphics card right now.

Look around on the web. There are moded drivers to re-enable this functionality. There is even patch to run Physx code directly on ATI GPU! The patch is obviously a much less conventional hack that can lead to system instability. I would only recommend this if you have a backup image of your C: drive and if you know exactly what your are doing. I don't even know if it's working right and what are the limitations, I only know it exist.

Re-enabling the functionality with a moded drivers should be quite safe. Just create a restore point before installing them. You can also choose to install Nvidia drivers prior to version 186 which are not plagued with this limitation. Since the Nvidia card in your system is only used for Physx functionality, it shouldn't be a big issue for you to use old drivers. Your main ATI GPU can still use the latest drivers.

[HW_90]

Look around on the web. There are moded drivers to re-enable this functionality. There is even patch to run Physx code directly on ATI GPU! The patch is obviously a much less conventional hack that can lead to system instability. I would only recommend this if you have a backup image of your C: drive and if you know exactly what your are doing. I don't even know if it's working right and what are the limitations, I only know it exist.

Re-enabling the functionality with a moded drivers should be quite safe. Just create a restore point before installing them. You can also choose to install Nvidia drivers prior to version 186 which are not plagued with this limitation. Since the Nvidia card in your system is only used for Physx functionality, it shouldn't be a big issue for you to use old drivers. Your main ATI GPU can still use the latest drivers.

and don't forget if you use an nvidia GPU with an ATi one then you need either XP or 7 as windows vista doesn't support multiple video drivers

[scottismo]

You will have no problem with such a supply should you want to build a decent rig.

Thanks for the quick response. I was already under the impression that a good 850W PSU (of which Corsair seems to be one) would handle anything I can reasonably throw at it for the future. However, it never hurts to be sure - it would be an expensive mistake to find out on ones own!

Thanks to Zak33 and ehhhhhhh also