Sapphire 5830 Memory clock < 550 Issue

[namley]

After a couple days of reading, and messing around mining with my nVidia Refference 8800GT and MSI Twin-Frozr 250GTS I decided to make a small investment into mining bitcoins.

I found a dam good deal on Newegg for Sapphire Radeon HD 5830 and tired of seeing my crappy 70MHash/s out of my overclocked nVidia Cards, I took the plunge and got 2 of the 5830's.
Link: http://www.newegg.ca/Product/Product.aspx?Item=N82E16814102878&cm_re=5830-_-14-102-878-_-Product

Figured may as well, even if I don't make anything back, I still got a decent pair of cards to run in XFire.

Current Setup
=================================
GA P55-USB3 Motherboard
Intel i5 720
2x Sapphire Radeon 5830's ( not x-fired )
2x Craptastic 550W PSU's

GuiMiner (poclbm)
Deepbit.net's MinerPool
=================================

Installation of the cards running stock, gave me about 200-216 MHash/s each
   - POCLBM Flags ( -v -w128 )

I tuned the cards using ATITrayTool
http://downloads.guru3d.com/download.php?det=733

I have been running the cards stable at 985/600 for 3 Days, using POCLBM Flags ( -v -w64 -r2 -f1 ) and getting 300-306MHash/sec
The fans are running at 100%, and I have a box fan blowing into the open case ** Yes sounds like a jet engine **

GPU Temps sit around 60-63C

I'm trying to figure out how on earth some of the 5830 users are getting their memory clocks down to 300. As soon as I go lower then 550MHZ Memory clock, the card crashes.

Any thoughts on why I can't lower my memory clock speeds, or suggestions.

Thanks

[1715020587]

1715020587

[1715020587]

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[1715020587]

1715020587

[bitlackey]

Avoid from 400 to 600, I've been using sapphire trixx which lets me jump to 300 without issue. With msi afterburner I have to set it around 600 and then restart the program to be able to set the 300 range. I switched back to afterburner for its multi-gpu monitoring.
I hope that helps, it works for me at least. I have the same cards.

I'm getting 308mh/s at 1000/350 using the phatk kernel & 2.1 sdk, I can't get above 290mh/s with the normal kernel.

[namley]

Oh okay, I'm going to try dropping the clock right down to 300 and see how it goes.

So I got it down to 300 no problem, but with my flags for POCLBM -v -w64 -r2 -f1 I dropped my Hash rate down to 273-277

Switched it to -v -w128 -r2 -f1 and Its sitting at 304-306 on both cards.

Current Temperature 58C
Fan 100%
Core Clock 1000MHz
Memory Clock 300MHz

[gigabytecoin]

Oh okay, I'm going to try dropping the clock right down to 300 and see how it goes.

So I got it down to 300 no problem, but with my flags for POCLBM -v -w64 -r2 -f1 I dropped my Hash rate down to 273-277

Switched it to -v -w128 -r2 -f1 and Its sitting at 304-306 on both cards.

Current Temperature 58C
Fan 100%
Core Clock 1000MHz
Memory Clock 300MHz

58C ?? How long are you holding that temperature at 1000mhz?

[namley]

Keeping in mind that I have both fans on the Cards running at 100% and a High RPM Box Fan running at full speed pointed to the open side of the case.

I will monitor for an hour and let you know. Its floating between 59-60C at the moment.

[namley]

Little sooner then 1hr, realizing that my ugly boxfan was on medium, I turned it to high

Top Card is sitting at 58C
Bottom Card is sitting at 60C

Both have remained at those temps for about 10-15minutes



How long have you ran your 5830's at those clock speeds? I was bit afraid of frying the cards.

[namley]

Monitored the temps for 30minutes

Sitting at

Top Card 57C
Bottom Card 58C

[styrfoem]

close to the same setup running here, 230Mhash/s per GPU, no OC. first attempted to turn Mem speed down on one card resulted in the same issues between 400-550MHz using MSI Afterburner.
i was stable at 600MHz and then after dropping to 550MHz i lost 4hrs troubleshooting and reconfiguring to isolate the issue to a single card and then getting it reset to the factory defaults. Will i was having the issue the video on the card that was turned down to 550MHz would allow login to Windows and then crash to a blue or sometimes blue with lines screen. (not BSOD tho) which i could only resolve with a hard reboot.

fyi - now using the solution here http://forum.bitcoin.org/?topic=6575.0 for the DVI solution on the 2nd card!!