AMD 6950 Undervolting and Overclocking with the Shaman

[sadbuttrue]

Final clocks
All of the following clocks have been tested extensively.

400/625  @ 800mV	Uses less power than the default dual monitor profile
650/1000 @ 900mV	The power of a 6870 at very low volts						
801/1250 @ 990mV	110mV less than stock 6950 @ 6950 clocks
880/1375 @ 1060mV	115mV less than stock 6970 @ 6970 clocks
910/1375 @ 1100mV	110MHz overclock at stock 6950 voltage
940/1375 @ 1175mV	60MHz higher than a 6970 at its default voltage

My clock profiles
400/625 @ 800mV - 24/7 desktop use with dual monitors
650/1000 @ 900mV - Video playback when PC used as HTPC and playing older games
940/1375 @ 1175mV - Playing modern games that need the extra ooomph


Test Bench

• i5 750 @ 3.98ghz Turbo Boost disabled
• Gigabyte P55 UD5
• 4GB G.Skill ECO 7-8-7-24-1T @ 1592mhz
• Corsair HX650W
• Samsung F3 1TB + Samsung F3 500GB
• Windows 7 64bit
• 6950 unlocked shaders with Shaman fitted - Driver version 11.3
• Raven RV02 with side panel removed and only middle fan spinning at 5volts
• Ambient Temperature 20.5c during all testing

Thermalright Shaman info
I have the shaman connected directly to the graphics card using this.
Fan speeds are as follows:

• 25% = 625rpm
• 50% = 930rpm
• 75% = 1170rpm
• 100% = 1280rpm

At 25% the fan is completely inaudible and barely spinning. At 100% the shaman is a fraction quieter than the stock fan at 25%.

Misc
A clockspeed of 801mhz was required to apply voltage adjustments in afterburner. For some reason it will not allow changes when running at the bios stock speed.
I have only included results upto 1.175v. In testing I found 1.225v was enough to activate the limiter in some games. As yet afterburner will not allow us to apply +20% power. Sapphire Trixx Will, but you cannot run below stock volts with that app (1100mV).


Stress testing
Furmark 1.8.2 20minutes @ 1680x1050 4xaa
Crysis Warhead 50 runs @ 1680x1050 DX10 Gamer 0xaa Ambush - higher load with AA disabled
Unigine Heaven 2.5 for 2 hours
4+ hours of actual gaming

• Load power consumption figures represent peak value rounded up to nearest 5watts
• Load temperatures are taken after 30minutes
• Idle power consumption is averaged over 10 minutes of inactivity
• Idle temperatures are taken after a quick furmark to bring temps up, followed by 10minutes of inactivity to allow them to fall

Power & Temps @ 100% fanspeed
Idle single monitor clocks of 250/150 are included. This shows my PC consumes roughly 100watts without a graphics card.

Core/Mem@mV	Idle			Crysis			Furmark						
250/150@900	121watts @ 27c		
400/625@800	134watts @ 29c		195watts @ 32c		190watts @ 34c
650/1000@900	147watts @ 31c		230watts @ 37c		225watts @ 39c

801/1250@990	157watts @ 33c		260watts @ 40c		255watts @ 42c
880/1375@1060	164watts @ 37c		275watts @ 44c		285watts @ 55c
910/1375@1100	166watts @ 37c		290watts @ 46c		295watts @ 59c
940/1375@1175	170watts @ 38c		310watts @ 51c		330watts @ 82c

When consuming more 330watts in furmark using lower AA settings, the Shaman would exceed 90c. I have no intention of killing my card, so at this point I abort.
The Shaman appears to have a cooling limit of ~200watts (330watts furmark - 100watts no card with ~88% power effeciency).

Temps by fanspeed

		25% 625rpm	100% 1280rpm
Core/Mem@mV	Idle Crysis 	Idle Crysis Furmark								
250/150@900	29	-	27	-	-
400/625@800	31	36	29	32	34
650/1000@900	33	41	31	37	39

801/1250@990	36	45	32	40	42
880/1375@1060	37	50	33	44	55
910/1375@1100	37	52	33	46	59
940/1375@1175	38	58	34	51	82

Did I mentioned the Shaman is inaudible at 25% fanspeed? Just look at those temps!

Benchmarks
All of these benchmarks are run at the hexus review settings. Crysis is a standard bench run rather than fraps, but the result is close enough. My scores are slightly higher due to using a newer driver.

Core/Mem@mV		Crysis	JC2	Mafia2	3DMark Vantage	
400/625@800		30.2	32.6	36.1	6659
650/1000@900		48.5	52.1	57.4	11173

801/1250@990		58.3	62.6	69.4	13434
880/1375@1060		62.8	67.9	75.2	14877
910/1375@1100		64.1	69	76.8	15233
940/1375@1175		65.1	70.1	78.6	15429

Below are the hexus results for various cards to compare against.

[CAT-THE-FIFTH]

Your title made me think of this group:

http://en.wikipedia.org/wiki/The_Shamen

Ebeneezer Goode:

http://www.youtube.com/watch?v=oPzv_EwxMl0

[ehhhhhhh]

it would have been nice to see some pics of the actual card

[a_dragon_jai]

thanks for the review, but in the graph was the testing figure on the 6950 overclocked while comparing with other cards/