Poor performance from 4850 CF, leads to crashes-help

[nard703]

As my somewhat vague topic implies, my computer is running 2 Sapphire 4850 HD 512mb cards in crossfire. I have updated the latest ATI drivers, CCC 10.11, crossfire profiles, set in complete default modes. When I benchmark test the 4850 HD alone, I get almost as much performance if not more sometimes, than I would in a CF configuration. From what I have read in other boards, this may be because I am running too little power to my entire system. My power source is a 500W Antec Earthwatts.

The rest of my specs are as follows:
Mobo: Gigabyte GA-MA790XT-UD4P Socket AM3
Chipset: AMD Phenom II X3 720 (790X, SB700)
Memory: 6 gb DDR3 OCZ
Processor clocked only to 3.2ghz using BIOS M.I.T.
GPU: 2 crossfired (using both bridges) 4850 HD 512mb cards

When I play games like Borderlands on highest settings, I get intermittent crashes to desktop or sometimes hard crashes in which I have to reboot...also just now my Google Chrome browser crashed the entire computer...not sure if it is interrelated though ;(

Any help or suggestions to improve my performance would be VERY much appreciated.

Thanks!

 

[shangshang]

looks like it could be your power supply, 500W is not enough. I remember those 4850 as being power hogs. Also, they're some of the hottest single slot cards (if not THE hottest) in recent memory, so 2 of them in 1 system could be overheating (causing crashes).

Furthermore, the ones you have are only 512 MB, so it's not worth it to CF them. If you're CF them, then you need 2 of them in 1GB versions. At 512MB, RAM will be the limiting factor. BTW, what resolution do you play at????

 

[borisvodofsky]

As my somewhat vague topic implies, my computer is running 2 Sapphire 4850 HD 512mb cards in crossfire. I have updated the latest ATI drivers, CCC 10.11, crossfire profiles, set in complete default modes. When I benchmark test the 4850 HD alone, I get almost as much performance if not more sometimes, than I would in a CF configuration. From what I have read in other boards, this may be because I am running too little power to my entire system. My power source is a 500W Antec Earthwatts.

The rest of my specs are as follows:
Mobo: Gigabyte GA-MA790XT-UD4P Socket AM3
Chipset: AMD Phenom II X3 720 (790X, SB700)
Memory: 6 gb DDR3 OCZ
Processor clocked only to 3.2ghz using BIOS M.I.T.
GPU: 2 crossfired (using both bridges) 4850 HD 512mb cards

When I play games like Borderlands on highest settings, I get intermittent crashes to desktop or sometimes hard crashes in which I have to reboot...also just now my Google Chrome browser crashed the entire computer...not sure if it is interrelated though ;(

Any help or suggestions to improve my performance would be VERY much appreciated.

Thanks!

CRASH DUE TO HEAT
CRASH DUE TO HEAT
CRASH DUE TO HEAT

This is one of the main reasons I didn't get 4850, most of them had single slot coolers that were NOT up to it. Even the dual slot cooler on the 4870 was not up to it.

Try open Case play a bit, and see if that helps.. Also (swap thermal paste duh...

And if it does not,, then try aftermarket cooling...

IT IS NOT your PSU.. No freakin WAY..

I used to have a 500watt powering the original dual core pentiums at 4ghz. and a x1900xtx with it.


THE ONLY problem i see here is aftermarket cooling requires seperate vrm coolers as well, so the cost is pretty high for a set of 2 gpu and 2 vrm coolers... you're actually better off bying a GTX 470,, hahaha...

It's up to you.. :thumbsup:

 

[nard703]

Thanks for the quick reply... I totally agree that they run very hot, I have about 4 fans in there to cool the system down during gameplay... I tried playing at 1920 x 1080 but had to scale down to 1700x1000 due to some lag issues (must be CF related)... my monitor can take it well (24" SyncMaster LED 1080p) but looks like I am VRAM limited huh?

so do you think I should just get rid of one of the 2 and overclock one of the 4850 cards to it's max (about 700 mhz GPU clock / 1050 Mhz High using ATI CCC).

thanks.

 

[nard703]

Thx TP!... I'm gonna run to Microcenter today and pick up an 850watt power supply and look to upgrading to a more solid video card if the extra power doesn't help out with the performance... any recommendations on max wattage for power supply?

 

[notty22]

Try taking off 1 bridge, just leave the one to the left, closest to the back of the pc. Some configurations respond strange to using 2.
Did you d/l install the separate AMD crossfire profiles ?
http://sites.amd.com/us/game/downloads/Pages/crossfirex-app-profiles.aspx

 

[nard703]

Notty, that makes some sense actually, I have heard people having worse performance using both bridges rather than just one, causing syncing issues... I'll try to use one bridge and reboot, also yes, I have the latest ATI crossfire profiles installed.. I believe the increased power supply should improve my performance though, seems to be a strong consensus!

Thanks all.

 

[GaiaHunter]

What temperatures do you read on your 4850?

If they are too high you can adjust the fan manually - the 4850 was a hot card due to low default fan speed (at least in reference designs).

I would say insufficient power is the main suspect, especially if that PSU is a few years old.

 

[v0id]

I have a very similar setup - x3 720, 2x 4850 512MB, high quality 500W PSU (Silverstone). For a while, I was having similar problems. After about 15-20 minutes playing a game, I would usually experience a hard lock.

I thought it might be the PSU as well, but tests using a power meter at the wall indicated that even at its highest the whole setup wasn't drawing more than about 300W. I thought heat might be an issue, so I bought a bunch of high quality GentleTyphoon fans for my case, and bought a bracket/fan that attached to the inside of the side panel on my case and exhausted hot air rising from the GPUs directly below, to the outside of my case. I also bought some small copper heatsinks and attached them to the VRMs on one of the two cards where they were exposed and not cooled by a heatsink. After all that my GPU temps drastically improved and the crashing stopped.

Hope this helps. Good luck!