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Overclocking pc133

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tripwire

Member
Joined
Jul 3, 2002
Location
Dixon, California
My friend and I are arguing about CAS latency for PC133 SDRAM. Plz, set us straight. His argument is that to overclock PC133, in the bios you Speed up the CAS Latency, and I say NO! If you upthe FBS, and change the SDRAM Timing, it will overclock, and I dont think there is a way to change CAS Latency.
 
Your correct, overclocking RAM involves upping the memory bus speed. You can set the CAS rating in the bios on most motherboards but it's just to run the memory at it's CAS spec.
 
For PC133 SDRAM you can set the cas latency to either 2 or 3. What those #'s dictate is the amount of time in between sending data and recieving it. So therefore changing from cas 3, to cas 2 can increase speeds a bit. In 3dmark 2k1 the difference from cas 3 to cas 2 is about 300 pts for me. But running ram at cas 2 can make your system unstabile and you can get errors at the worst time (when your system is running very hard most often). You can buy ram that is meant to run cas 2, in PC133 it is usually about 5-10 $$$ more per stick. All that you can do to see if your ram will run at cas 2 is to try it. As far as overclocking your memory, you just do that through a higher fsb. When you overclock using the fsb you are actually overclocking everything, cpu, memory, pci/agp.
 
Also important to note, you won't be able to achieve as high of a FSB with the cas latency lowered to 2. However sometimes (usually) the performance gain from cas2 will outweigh not being able to overclock the fsb as high.
 
I suppose that if the ram is rated for 3-3-3 and you run it at 2-2-2, you are technically overclocking it, in that you're running it faster than it was rated to be run ... ;)

But they're all right -- you'll generally overclock RAM (and everything else) by upping the FSB. Try to go as high as you can by 2-2-2 first, then 2-3-3, and test for stability (use memtest86 or the likes). When that konks out, move to 3-3-3, which should be able to go much higher.

On my Micron 256 MB CL3 modules, I can go to about 136 MHz with 2-3-3, then 3-3-3 all the way to 156 MHz.

-- Paul
 
wilhelm310 said:
how high can pc 100 go?

Well obviously it is rated to do 100, but just like any ram, based on the brand, mfg date, and many other variables it may go higher. Some pc100 sticks are probably just 133 sticks sold as 100's and such. You really just have to find out yourself... maybe it will only do 101, maybe it will do 150.
 
Yeah the memory I have is a lower brand, it just says hynix and it does 155 cas2, two sticks bought from the same store about 4 months apart, lucky huh!

Btw it was pc133. and 100% stable
 
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