Question about overclocking my 5850's

[mike678]

I want to preface this with the fact I know how to overclock cards I've been doing it with my 5830's for a month and a half.

So I recently picked up the 5850 from ncixus and they arrived yesterday. One thing I noticed is if I drop the memory to around 300 the card start acting up and becomes unstable. I've seen multiple time people who have 5850's recommend this speed?

Another thing thats weird is if I go to 970 core clock or above the system freezes the moment I hit apply. The reason I ask is because when my 5830's get overclocked too high the drivers just crash but it doesn't freeze the entire system. Do the 5850's just act different when overclocked?

I assume all this means is that I can't get stable overclocks over 970 but the cards are acting strange compared to my experience with 5830's.

[mike678]

any one?

[deslok]

The memory issue i've noticed across my cards 5770-5830-5870 the higher end cards don't like the lower memory frequencys the 5870 not liking anything below 450 the 5770 allowing speeds below 300. as far as your hard crash i've seen it on all 4 if i push them too far likely your 5850 has less headroom (possibly bad luck) than your 5830 all of my cards have been able to run at 1ghz sofar good luck it seems if nothing else.

[mike678]

The memory issue i've noticed across my cards 5770-5830-5870 the higher end cards don't like the lower memory frequencys the 5870 not liking anything below 450 the 5770 allowing speeds below 300. as far as your hard crash i've seen it on all 4 if i push them too far likely your 5850 has less headroom (possibly bad luck) than your 5830 all of my cards have been able to run at 1ghz sofar good luck it seems if nothing else.

Yea all 5 of my 5850's from ncixus crash my comp at some point between 945-975 mhz. It's not too bad though my average speed between the cards is 390 megahash because of my tweaks so its still a great card at $145 I just wasn't able to push them as high as I wanted.

[Chris Acheson]

Some cards will just get unstable or immediately crash when you lower the memory clock.  It has to do with the brand and model of card, but not with whether it's a high or low-end card.  I had an XFX 5870 that would crash if you set the memclock to 400 or lower, but my Diamond and Power Color 5870s worked fine at 300.  Same goes for raising the core clock.

[mike678]

Ah I just wish it was easier to test the limits of these cards. My 5830s don't full on crash my system the moment they become unstable so I got them to the best speed a lot faster and I'm still working on optimizing these.

[hdfxst]

what are you using to lower the speed?when i used afterburner i had this same problem,with trixx i can lower the speed to 300 with no problems

[mike678]

Yea I switched over to using trixx a couple days ago and it works fine. Afterburner for some reason was really glitchy.

[CanaryInTheMine]

Mike,

I've got the same cards from same place as you.  No issues with setting them to 300 mem.

use AOCLBF: https://bitcointalk.org/index.php?topic=10264.0
to overclock.  I think I recommened this to you quite a while back on one of your prior posts where you put up a bounty for solving msi afterburner issue you had.

also, I'm actually running them at 300 and slightly under-volted @ 1050 without any issues.

hope this helps you.

[mike678]

Mike,

I've got the same cards from same place as you.  No issues with setting them to 300 mem.

use AOCLBF: https://bitcointalk.org/index.php?topic=10264.0
to overclock.  I think I recommened this to you quite a while back on one of your prior posts where you put up a bounty for solving msi afterburner issue you had.

also, I'm actually running them at 300 and slightly under-volted @ 1050 without any issues.

hope this helps you.

With a mix of trixx and 11.7 I am running them at 920/325 now. Thanks for trying to help though

What's your megahash speed and clock/mem speed?

[CanaryInTheMine]

anywhere from 920-940 /300 @1050 voltage, fans from 60-75%. depends on the rig they're in.
hashing from 380-401

[teukon]

anywhere from 920-940 /300 @1050 voltage, fans from 60-75%. depends on the rig they're in.
hashing from 380-401

This sounds like a very good setup to me!

Perhaps I misunderstood but it sounds like you can get over 400 MH/s from a 5850 at 940/300?  May I ask which OS/Catalyst/SDK/kernel?  I'm also curious what Mh/J you're getting.

[mike678]

anywhere from 920-940 /300 @1050 voltage, fans from 60-75%. depends on the rig they're in.
hashing from 380-401

This sounds like a very good setup to me!

Perhaps I misunderstood but it sounds like you can get over 400 MH/s from a 5850 at 940/300?  May I ask which OS/Catalyst/SDK/kernel?  I'm also curious what Mh/J you're getting.

I can do 940/325 I just don't because I can't stand the heat blowing on me. At that oc I get ~395. I'm using pheonix 1.5, phatk kernel 2.2, 11.7 , 2.5 sdk and win 7 32 bit

I'm curious where he gets the extra 5 from.

[teukon]

anywhere from 920-940 /300 @1050 voltage, fans from 60-75%. depends on the rig they're in.
hashing from 380-401

This sounds like a very good setup to me!

Perhaps I misunderstood but it sounds like you can get over 400 MH/s from a 5850 at 940/300?  May I ask which OS/Catalyst/SDK/kernel?  I'm also curious what Mh/J you're getting.

I can do 940/325 I just don't because I can't stand the heat blowing on me. At that oc I get ~395. I'm using pheonix 1.5, phatk kernel 2.2, 11.7 , 2.5 sdk and win 7 32 bit

I'm curious where he gets the extra 5 from.

At 940/325 I get about 396 Mh/s (phoenix 1.5, phatk 2.2, Catalyst 11.6, SDK 2.1, Linux 64-bit).  As always, SDK 2.4 and SDK 2.5 are 2 Mh/s slower than SDK 2.1 and Catalyst 11.7 makes my system unusuable (all of which I think are Linux peculiarities).  Other than this on only two occasions were people claiming of hash-rates for a given clock on a 5850 that were simply out of my reach and two of them were using Catalyst 11.4 (in both cases they were about 7 Mh/s faster per 5850).  I tried Catalyst 11.4 but experienced no speed boost so perhaps this is a Windows thing or perhaps there are several different 'Catalyst 11.4's.

I also don't run at this speed typically though because of the increased heat, power consumption, and noise.  My cores are at 847 MHz and 899 MHz right now.

[mike678]

At 940/325 I get about 396 Mh/s (phoenix 1.5, phatk 2.2, Catalyst 11.6, SDK 2.1, Linux 64-bit).  As always, SDK 2.4 and SDK 2.5 are 2 Mh/s slower than SDK 2.1 and Catalyst 11.7 makes my system unusuable (all of which I think are Linux peculiarities).  Other than this on only two occasions were people claiming of hash-rates for a given clock on a 5850 that were simply out of my reach and two of them were using Catalyst 11.4 (in both cases they were about 7 Mh/s faster per 5850).  I tried Catalyst 11.4 but experienced no speed boost so perhaps this is a Windows thing or perhaps there are several different 'Catalyst 11.4's.

I also don't run at this speed typically though because of the increased heat, power consumption, and noise.  My cores are at 847 MHz and 899 MHz right now.

Yea I cant test 11.4 because I have 5 cards so I'm stuck with 11.7 or later. I might try downgrading my sdk to 2.1 and see what happens.