Is there a "speed step" with modern GPUs?

[Antoneo]

I was just wondering if the GPU on today's video cards have either thermal protection (clocks down when temperature is too high) or speed step like capabilities when there is not enough power.

 

[sparkyclarky]

The 6800Ultra has some sort of power thing if only one molex is plugged in. But I don't believe any modern desktop GPU has the features you're describing (or at least not anything in the same league as a CPU).

 

[VirtualLarry]

Well, more or less they actually do have similar features, except they aren't (to my knowledge) triggered automatically by the hardware, but programmably by the drivers. GPUs have been frequency-programmable ever since the Voodoo1, mostly, using programmable clock-generator chips onboard. Newer GPUs also support programmable VRMs on-card, and generally they have a slightly higher-voltage setting when in "3D mode" (as controlled by the driver), vs. when they are in 2D-only mode.

(That brings to mind a question - since Longhorn's new Aero UI will use advanced 3D card features to render the basic Windows' UI, won't that mean that the card will be in the higher-powered "3D mode" all of the time? Sounds like they will generate a bit more heat then too.)

 

[otispunkmeyer]

didnt the 5800 speed up n down depending on what it was doing?

 

[sparkyclarky]

Originally posted by: otispunkmeyer
didnt the 5800 speed up n down depending on what it was doing?

The 6800 series does this too. But the OP is talking about power management issues and thermal protection.

 

[modedepe]

Originally posted by: otispunkmeyer
didnt the 5800 speed up n down depending on what it was doing?

Yes, both that and several other cards. Also there is an option to change the core slowdown threshold built into the drivers.

 

[MDE]

Originally posted by: modedepe

Originally posted by: otispunkmeyer
didnt the 5800 speed up n down depending on what it was doing?

Yes, both that and several other cards. Also there is an option to change the core slowdown threshold built into the drivers.

The entire FX series as well as the GeForce 6 series have separate 2D and 3D core clock speeds.

 

[uOpt]

Both my cards clearly have power management. The power consumption varies a lot depending on workload.

I don't know whether they have any kind of protection. My GeForce 4 and 5200 don't even seem to have a temp sensor, but the 5900XT does.