I've never really been into overclocking GFX cards, but since i just upgraded to 2x5850 HIS with Icooler V's i was wondering what would be a stable overclock for them, and which program i should use to overclock them.
This may seem strange, but do you really need to overclock them right now? I'd think that two HD 5850s would be able to handle pretty much every game on max settings at 1080p, with the exception of games such as Crysis, Metro 2033 and possibly Shattered Horizon.
If you do want to overclock your graphic cards, you can do so with ATi OverDrive in the Catalyst Control Center, to a certain limit, 775MHz on the core I believe. Otherwise if you want to pass that limitation you'll need to download ATi GPU Clock Tool, otherwise flash your HD 5850s' BIOSes to ASUS versions which don't have the limitation IIRC.
was just wanting to learn how tbh, never really got into overclocking gfx cards. I know they r plenty strong enough to run all the games on the market, but just wanted to toy with them for a learning experience.
Crossfire 5850s has some issues using OC apps. MSI Afterburner for example generally will cause a crash if you try to OC.
I just upgraded to a 2nd card. When I had 1 card, at stock volts I was able to get it rock solid at 875/1200. I used MSI Afterburner. I then BIOS flashed the card so that it runs 875/1200 in 3D and 157/300 in 2D (if you just use a program for OC, it won't downclock at 2D).
The absolute max stable OC on my card was 985/1200 with 1.225V
When I got my 2nd 5850 I was having some issues overclocking it. I flashed it but I think it didn't work right, I ended up reflashing both to stock and then it worked. After that I reflashed again with the OC BIOS and it's now working great. Crysis on Very High 2xAA 1920x1080 and it's 50+ FPS, minimun still around 40 FPS. It runs fine at 4xAA as well until I zoom in then it drops to 20FPS... and honestly I don't see a graphical difference between 2x and 4x in this gorgeous game.
Anyway, what you want to do is first disable crossfire. Then start trying to OC with Afterburner until you find a good stable OC that you like. After that, check out RBE bios editor along with ATIFlash (or ATIWinFlash) and you can custom set your GPU BIOS. Note that this isn't for "noobs" you'll want to read the tutorials and forums to see what issues people have had. Bios flashing technically voids warranties and there's a possibility to "brick" your cards although IMO that only happens if you do something stupid.
and what way would u suggest doing this, i still want them to drop to 2d when idling if possible, i'd rather not flash the cards though.
Flashing is about the only option for doing it automatically. And since there's a known issue with Afterburner and crossfire, it might be the only option. I guess you can try finding a different OC utility like ATI GPU Overclock Tool but I've never used that one. It is possible to flash with a BIOS that will allow higher overclocking in CCC rather than edit the default clocks, but you're still flashing them.
Flashing isn't too hard, I used ATIWinFlash although it's recommended to use ATIFlash from a DOS boot disk, I just couldn't get the boot disc to work properly. I also had to disable crossfire to do it since it only flashes one at a time. So long as you do one at a time, if one screws up you can use the other card to boot up the reflash the bad one with the default BIOS.
Yes, there is some risk but imo if you're overclocking it's already a risk.
One issue tho is that flashing with a different fan profile only works during boot up, for some reason when windows loads it takes over the fan profiles to the really low defaults so I still need to run Afterburner for the custom fan profiles. I've read people are trying to get around it, apparently something about the registry might be causing it but I don't know enough about it.