PAT (Performance Acceleration Technology) doesn't work at higher than 200FSB with 4 sticks RAM?

[Almighty1]

Greetings all:

I have a ASUS P4C800-E Deluxe Motherboard and it seems like with my memory at 1:1 ratio (400 on the ASUS), and Performance Acceleration Mode set to Enabled, the FSB at 200 will show PAT Enabled under the Memory tab in CPU-Z 1.19 and SiSoft Sandra MAX. However, at 230-233FSB, it will show PAT as disabled, is this the way it's supposed to work because I have it enabled in the BIOS. This is a P4C-3.2Ghz CPU at stock voltages. The RAM is 4 sticks of matched Hynix PC3200 DDR400 512MB CL3 running at 3-3-3-8-8 at stock voltages which came from a Dell Dimension XPS.

 

[bacillus]

hmm, not exactly sure what your problem is but PAT works for me at 240fsb 1:1?
have you tried just using 2 sticks of ram?

 

[Ketchup]

The way I understood it when the 875P was first released, PAT only works at 200 FSB. When you overclock or use a 133 FSB chip, PAT is not enabled.

 

[Almighty1]

Originally posted by: bacillus
hmm, not exactly sure what your problem is but PAT works for me at 240fsb 1:1?
have you tried just using 2 sticks of ram?

Just a update, it seems that with PAT, at 233FSB, with one set of dual channel 512MB Memory, the PAT is enabled and the memory bandwidth benchmark in SiSoft Sandra MAX works but when I place both sets (all 4) of the same batch memory, PAT is disabled and then SiSoft Sandra MAX's memory bandwidth benchmark just flashes through the part where it usually does the test and shows 0MB/sec bandwidth. Does PAT work only on one set of RAM and not two sets?

 

[Sunny129]

there are all sorts of stringent requirements for PAT to be enabled. going above a certain fsb, using certain RAM configurations, OCing your chip, etc. all affect whether PAT will work or not on an 865 board...at least that's what i'm getting out of my research here. but since you have an 875 board that's supposed to have PAT, the requirements shouldn't be as stringent. however, i do think the memory issue holds, at least for early versions of PAT in early BIOSes. make sure you have the most recent BIOS, and you may not have that PAT/memory issue anymore. but i do recall anand touching on the issue in one of his memory or motherboard articles here, so you might want to search in the articles as well...

 

[Almighty1]

Originally posted by: Sunny129
there are all sorts of stringent requirements for PAT to be enabled. going above a certain fsb, using certain RAM configurations, OCing your chip, etc. all affect whether PAT will work or not on an 865 board...at least that's what i'm getting out of my research here. but since you have an 875 board that's supposed to have PAT, the requirements shouldn't be as stringent. however, i do think the memory issue holds, at least for early versions of PAT in early BIOSes. make sure you have the most recent BIOS, and you may not have that PAT/memory issue anymore. but i do recall anand touching on the issue in one of his memory or motherboard articles here, so you might want to search in the articles as well...

Problem does happen with the latest BIOS. It appears that it only happens with 4 sticks. I am using Corsair XMS PC4000 now though.