4890 Running Hot - 12/03/2009
I've used ATI and nVidia graphics for a long time currently using strictly ATI
you may need to use RBE Radeon Bios Editor to fix things and you may need some after market coolers.
I have a Saphire 3850 AGP 512MB
The thermal death of my nVidia 6800 ultra oc tought me to buy only heat pipe coolers which now so lovingly grace todays video cards.
I replaced the stock cooler of the Saphire 3850 AGP with an Accellero Twin Turbo Cooler which came with heat sinks for the ram.
Bios Editing for the Saphire 3850 AGP models:
The bios of the Saphire Radeon HD 3850 AGP is a special bios
The RBE_122.exe program looks at the Saphire Radeon 3850 AGP as two different bios chips , "Rialto and RVxx"
Thats because of the magic pcie to agp bridge used to create them.
RBE_122.exe may hang and not allow you to select the RVxx as a choice and so a bios adjustments may not be possible under version 122
and from what I've read it may not even be reasonable to ask to edit the 3850AGP
( if that happens you may need to use some kind of third party analgue or digital fan controler to control fan speeds on your video cooler and you may have to build your own connectors )
I also have a Power Color AX4890 with a 950MHz Core and 1050 GDDR5 pcie
it's by far the hottest running of the DX10.1 class GPUs.
( some models of 4890 sent to china already have dual fan and 4x heat pipes )
Accellero Twin Turbo Cooler fits the AX4890 with a small modification of the fins to get them to slide over the back taller power regulator heat sink.
I was using mine on my 3850 AGP but now am using it on the AX4890
and using the stock 3x heat pipe from the AX4890 on my 3850 AGP
Temperatures are now perfect on my 3850 AGP
Bios Editing for the AX4890:
RBE_122.exe and AX4890 pcie 1GB play nice together.
I've modified the fans only using the Transfure Function Method (recommended) and my personal settings are
Tmin(C°) = 40 Duty Cycle Min (%) = 50%
Tmax(C°) = 55
Tslop = 53%
That tells the Accellero Twin Turbo that when the core is 40°c to run at 50%
as the core rises to 50°c the fans will run at 60%
If you just flashed yours:
before any ATI CCC / ATI OverDrive changes
before you click on the pad lock to enable the over clock settings
The GPU will be at 500MHz core speed , and memory will be 1050MHz
in open air, on a table, in a room, with a temperature of 75F +/- 5°
GPU Core Temperature will be at 50°c to 55°c
or warmer if you don't have any fan on the back side doing some back side cooling.
If you want to cool things down from there
Click on the padlock to unlock your overclock settings
You can set the core to 800MHz and memory to 1050 or lower to reduce temperatures and save power which is whats really cool about these newer cards.
The core temp of the AX4890 is not as important as the GPU DIODE ( MEMIO ) temp
it reads much higher than the core and you don't want that going too high , 50°c to 60°c is what you should see for it's idol temp.
You may need to clock the ram all the way down to 525MHz and core down to 800MHz before seeing less than 50°c on the GPU DIODE ( MEMIO ) - thats still 1050MHZ effective for GDDR5 which does more work per clock than previous types.
Remember you do not need to raise clocks while in idol mode
You only need to raise your clocks when you're
1. Bench Testing
2. Running a graphicaly intense application like a video game
3. Experience Lag while running a graphicaly intense application
I hope this post helps put others at ease about their temperatures.
