P3V4X memory timings

[jkersenbr]

Today I decided to tinker with the memory settings on my P3V4X too see if I could help my Sandra benchmark scores anyway, and I noticed something interesting the scores. I'm using a 128MB stick of Kingston PC100@133. The BIOS on my board is revision 1005.

Speed set in BIOS as "BY SPD" = Sandra score 248/296
Speed set as 3-3-3-6 = 219/242

Hmmm, why the difference? Even on the first setting, the speeds are set 3-3-3-6. I found out why -- when using the "BY SPD" setting, the BIOS enables 4X interleaving. If the speeds are set manually, only 2X interleaving is enabled.

Anybody seen this before? Or do I have a wierd one?

If anyone is curious, using H-Oda's WPCREDIT, I did some more tweaking and found the following:

2-3-3-6 2X interleave = 226/259
2-2-2-5 2X interleave = no post (rats!)
2-2-3-6 2X interleave = no post
2-3-2-6 2x interleave = 241/280
2-3-2-5 2x interleave = 244/279

2-3-2-5 with 4X interleaving enabled = 270/330

This is pretty much as fast as my ram will go. O well, with 4X interleaving this Via chipset doesn't look too bad!

 

[subhuman]

Hmm, the benefits of CAS2 PC133 ram are interesting, on the same board, with CAS2 ram, you can get 400/465 optimally..

 

[LocutusX]

Yup, P3V4X likes CAS2 alot. But doesn't everybody?
Too bad I have to run all my RAM at CAS3 because one of my sticks doesn't like CAS2.

 

[rpr]

I get the same thing (4x interleaving only with SPD). Good find! Unfortunately, it doess't help me. SPD gives me 3,3,3,6. I can run stable by manually setting 2,2,2,5. My benchmarks at 2,2,2,5 with 2x interleaving are about 20% higher than 3,3,3,6 (SPD) with 4x interleaving.