NEWS: Windows XP SP2 Dual Core Performance Fix

[Handruin]

Microsoft has released a hotfix to improve performance on dual core systems. It fixes a possible decrease in performance during demand based switching. Cool 'n Quiet must be enabled for the fix to work, and Microsoft will only send you the hot fix if you have been experiencing the problem. The issue is how do you know if you are or not? AMD told me this can have an impact on some games although I've not heard of any problems, and my main gaming system is an Athlon 64 X2 3800+ at the moment. Here are some additional details.

Possible decrease in performance during demand-based switching
Demand-based switching refers to the changing of ACPI processor performance states in response to system workloads. For example, demand-based switching can change voltage and frequency in response to system workloads. Windows XP processor power management implements demand-based switching through the Adaptive processor throttling policy. The Adaptive processor throttling policy dynamically and automatically adjusts the processor current performance state in response to the computers CPU use. The Adaptive processor throttling policy works without user intervention.

Source Link

Hotfix

 

[Will Rickards]

So I guess running F@H in the background solves this problem?

 

[sechs]

Let's call it a "work around."

 

[Will Rickards]

Where does one turn off cool n quiet anyway? In the BIOS?
I think I turned that off anyway.

 

[Mercutio]

I am under the impression that it's a driver one needs to load.

 

[Groltz]

It is a bios function on my K8N Neo4 Platinum motherboard. (Disabled)

 

[Mercutio]

Important thing to note, now that I've done it a few times:

After the installation of an x2 processor on a machine with an existing Windows installation, Windows must be reinstalled before it will take advantage of the second processor.

I feel like an idiot, 'cause I've had a few x2s running for about a month now, that I never bothered to ensure were actually USING the second core. I noticed last night that the computer type in Windows 2003 was still "ACPI computer" and not "ACPI multi-processor" or whatever it's supposed to be, then checked Task Manager and found only one CPU graph instead of two.

D'oh!

Microsoft made a kernel upgrade tool for Windows 2000, but I can't find any such thing for XP or Server 2003, so I just reimaged the affected machines.

Something else I found out: 450W HEC PSUs can't handle both x2 cores + 5 7k250s + midrange PCIe graphics cards + 2 1GB sticks of RAM. Two of the three machines I have would die during the hardware detection phase of the sysprep mini-setup. I disconnected some drives and they came up fine. Now I have to buy #$%ing new $100 PSUs just to use the processors I bought.

 

[mubs]

Let us know what size PS works, Merc.