4870x2 Crossfire - Poor Performance

[SkitZaY]

Hey Guys,

Recently got a new system with specs listed to the left. It seems, although the performance is good, it is nowhere near what it should be.

One thing to note, is that I am getting capacitor squeal from my PSU (this has been confirmed), and I will be replacing it with a Corsair HX1000. Is it possible for power limitations to cause this reduced performance?

NOTE: I understand ATi is not optimized for Crysis, but this is quite poor none the less. Only other game I have installed ATM is Stalker: CS, which also runs quite poor at some points.

Specs for Crysis all maxed, 1680x1050 resolution with 4xAA. You'd think that if one 4870x2 could handle this quite well, then why would 2 pull out frames from 17-30.

Currently running Catalyst 8.9, attempting as we speak to uninstall drivers and reinstall (driver cleaned ofcourse).

Any help would be appreciated guys,
Cheers

[Stukov]

Crysis and Stalker CS are probably the two worst games to test your cards on. CS isn't even profiled to use 1 card, let alone 2. Crysis scales like 10-20% going from 1 4870 to 2, I doubt you are going to get anything else out of it with CF.

A game like FEAR, Stalker SOC, etc will scale well with 1 card, I don't know about 2. And you aren't going to to see hardly any benefit from 2 X2's at that resolution, I mean, like zero. You would need a 20Ghz Quad core to do so. If you are going to spend another 550 dollars on another card, you would have been better off buying a 30" or at worst 24" screen (2560/1920 resolutions).

You might, just maybe see a FPS increase with running 32x FSAA or something, but that 2nd X2 is pretty much useless at that resolution.

[SkitZaY]

The larger monitor is a W.I.P, system has been purchased in prep for the larger monitor. I am also aware that one 4870x2 would be plenty for this resolution, but the problem is that 2 in crossfire are performing worse (obviously in the tested games) than people / reviews with one card. I can understand that scaling would be poor in some games, even nonexistent, but that doesn't quite explain why my performance is all around lower then it should be.

I don't expect magic or a quick fix, just looking for some suggestions.

Cheers.

[mitzi76]

found my cpu was running at 2000 ghz (well i think 2,66ghz under load). O'cd it to 3.4ghz 20 fps increase at least.

however am hearing you on the low perf..I tried crysis at 1920x1200 at 2x aa low setting and was getting around 65 fps. however anything higher and I got strange things happening with the sky.

am very tempted to send mine back (1day left to decide). if i could summ the power id take out the 4870 x2 unistall drivers and put back my old 9800gtx to compare.

[freeZ]

I also recommend OC'ing. With the 4870x2 I noticed a huge performance gain going from 3GHz to 3.6GHz.

[Orthello]

The 4870x2 is not that bad in crysis. I think you do need a fast cpu to get the most out of hit however. My brother and i did some tests.

All in Vista 64, 4gb ram. (this is the best os for the 4870x2 , especially with AA on).

My brothers rig which is a GTX 280 SLI setup @ 4ghz dual core setup gets 44 FPS in crysis in the 1st GPU benchmark 4x AA 1920 x 1200.

My setup 4870x2 oc'd to 850/1000 , dual core cpu @ 4.675 mhz gets 47 fps in the same test.

Yes i have a few mhz on him but really if he had the same cpu the figure would be similar from my testing on cpu gains anyhow.

[SkitZaY]

It's not a bottleneck, it's just general performance issues by the looks of it. Bear in mind my CPU isn't exactly poor stock, the Q9550 @ 2.83 (stock). That should be pulling well over 20fps with crossfire 4870x2s in Crysis at such a low res (1680x1050).

I'll try OCing my CPU when I get an aftermarket cooler though, but I don't think that's the problem.