underclock the RAM on a 5850

[shamen]

Hiya
Ive got my 5850 running at 366MH/sec with 945mhz/1200mhz RAM (modded 5870 bios). Ive read (admittedly conflicting) reports about downclocking the RAM to 300mhz to get a MH/sec boost.  Id like to give it a try. Ive added thwe following into MSI afterburner:

[ATIADLHAL]
EnableUnofficialOverclocking   = 1
UnofficialOverclockingEULA     = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode     = 2
AccessibilityCheckingPeriod    = 0

and changed the unlock voltage parameter

UnlockVoltageControl      = 1

However I seem to only be able to reduce the RAM clock to 600mhz minimum in MSI Afterburner. In ATI ccc, its 900mhz maximum downclock.

What am I missing?

[1715435236]

1715435236

[1715435236]

1715435236

[1715435236]

1715435236

[1715435236]

1715435236

[gigica viteazu`]

try AMD GPU Clock Tool from TechPowerUp

[shamen]

Hiya,
Cheers

I gave that a shot but its saying 'no suitable device found' . Bummer.

Other tools show up the card just fine, they just dont let the ram clock go below 600. Still, its doing ~370/MH with that setting ATM.

[Wuked]

have you tried using -w256 as well ? gives me 5 or so more Mh/sec

[shamen]

Yep, gives me about 5MH/sec *less* though

One of the reasons I wanted to try 300 on the RAM, to see if worksize 256 would help

[slaithe]

Hiya,
Cheers

I gave that a shot but its saying 'no suitable device found' . Bummer.

Other tools show up the card just fine, they just dont let the ram clock go below 600. Still, its doing ~370/MH with that setting ATM.

Same, here.  This is what I've found works thus far with my Sapphire 6950 unlocked to 6970.

1. Disable AMD Overdrive in CCC.
2. Use MSI Afterburner (after unlocking in cfg file) to set mV to 1.200
3. Use ATI Tray Tools to set Core 960 Mem 322 and Fan to 64%.
4. Use GPU-Z and set all Sensors display to Current Reading to ensure my settings are active and persisting.

For some reason ATI Tray Tools won't correctly set voltage, for me.  With the above, I'm getting 400Mh/s consistently while currently hovering around 70C.  I have headroom to experiment a little more, later.  I'll just revel in having reached the 400Mh/s sweet spot for a while and monitor system stability.

[slaithe]

Same, here.  This is what I've found works thus far with my Sapphire 6950 unlocked to 6970.

1. Disable AMD Overdrive in CCC.
2. Use MSI Afterburner (after unlocking in cfg file) to set mV to 1.200
3. Use ATI Tray Tools to set Core 960 Mem 322 and Fan to 64%.
4. Use GPU-Z and set all Sensors display to Current Reading to ensure my settings are active and persisting.

For some reason ATI Tray Tools won't correctly set voltage, for me.  With the above, I'm getting 400Mh/s consistently while currently hovering around 70C.  I have headroom to experiment a little more, later.  I'll just revel in having reached the 400Mh/s sweet spot for a while and monitor system stability.

I've been having stability issues, so I've dropped back to 1.175mV and 950/300, looks like I'm still maintaining 400Mh/s, though.  Guess I can lower the fan, then!

[shamen]

I've been having stability issues, so I've dropped back to 1.175mV and 950/300, looks like I'm still maintaining 400Mh/s, though.  Guess I can lower the fan, then!

wow 400 @ 950 is nice. Im going to try getting the ram down to 300 or maybe 280 tonight and see what I get. Heres hoping I hit near the 400 that you have!!

[Wuked]

AMD GPU Clock Tool will let me put the memory on my 5850s down to 200... but it won't let me change the voltage

[shamen]

AMD GPU clock tool still wouldn’t load. However I found a way to get MSI afterburner to allow the 300mhz downclock

-Ensure settings in afterburner config file are as above in post #1
- Start MSI afterburner and enter your over/underclock settings
- Set RAM to lowest possible setting and apply
- Exit MSI afterburner
- Reload MSI afterburner
- RAM settings should now go down to 300

375MH/sec @940/300 with worksize 256

[Wuked]

That's nice - I'm getting about 360 at 915Mh

[python]

366MH/sec 5850

[fadisaaida]

i m using trixxx from saphire and so far having great results :

my configuration is : 900mhs clock, 300 ram ( though it shows 1200 in trixxx for some reason), and voltage of 1.156, Temp on trixx show a maximum of 67 after few hours of machine running. fan is on 90-99% using stock cooler, and getting 370 mhs/sec.