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Memory vs CPU speed

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MRD

Senior Member
Joined
Feb 14, 2003
I have an ASUS a7n8x mb with an amd athlon xp 2100+ processor. The processor is supposed to run at 13x133.

In the bios, I have set the external speed to 133. However, the bios autodetects the memory as 166.

I don't really understand how the memory speed and cpu external speed can be different. Is this a problem? Maybe I'm missing something here.

Thanks.

MRD
 

Top Hat Theater

Member
Joined
Jul 24, 2002
Location
Lost in Thought
Are you runnnig PC2700 RAM at SPD settings? If so, that'd explain why it's running at 166. Also, you can run yoru memory out of sync with the FSB however on AMD systems, it isn't very effective. BTW, is your CPU a Thoroughbred B? If so, it should run 13x166 without a problem.

~THT
 

ManOfKnight

Member
Joined
Jan 26, 2001
Location
Back in Iowa :( Come on Gators, Get up and Go!
MRD WELCOME TO THE FORUMS!!!

Also just as stated above, your memory is probably a PC2700 or 166Mhz DDR. It is OK to run your memory async...although you are not going to see any gain out of running it that way. I suggest seeing if your processor is unlocked (meaning you can change the multiplier)...if so you should see if you can overclock your 2100 a bit. Although if it is a TBred B as stated above you should have NO problem just going to 166 on your processor FSB and running your ram and cpu sync.
 
OP
MRD

MRD

Senior Member
Joined
Feb 14, 2003
Sorry I forgot to mention that. Yes, I purchased PC2700 DDR ram. I figured since the mb is a 333 I would go with the PC2700 so I could upgrade the processor at a later date. I was running it at SPD, which is why it autodetected to 166. I was unsure if running async would be a problem. You mention it isn't much benefit though, why is that?

I'm not sure if the cpu is a thoroughbred or palomino core. How can I check this? If it's a palomino, will it not be able to handle the 166 external frequency?

I was getting random reboots (in both linux and win 2k, so not OS related) running the memory and cpu async and was wondering if that could be the cause.

Thanks.

MRD
 

johan851

Insatiably Malcontent, Senior Member
Joined
Jul 24, 2002
Location
Seattle, WA
It might be the cause, but it could also be a number of things. Your memory might be bad...what brand is it?

The reason you don't get much gain running async is because the processor can't utilize the extra bandwidth gained by running the memory faster. If you can get the processor and memory running together (syncronously) at 166 then the processor can utilize the extra memory bandwidth.

A Palimino core probably won't be able to overclock to 166fsb, at least not without a little voltage. A TBred B should do it with no problems.

If nothing else, try setting your memory ratio from automatic to 1:1, or 6:6, or whatever - just set it to run in sync. That *might* fix your rebooting problems.
 

Top Hat Theater

Member
Joined
Jul 24, 2002
Location
Lost in Thought
In my experience, async has only made stability worse.

To determine the core of your CPU, look at the die. If it's a square, it's a Palomino. If it's more of a rectangle, it's a Thoroughbred. To determine if it's an A or a B, look at the stepping. If it ends in "A" like AIRGA, it's a Tbred A. Likewise, if it ends in a "B" like AIUHB, it's a Tbred B.

~THT
 
OP
MRD

MRD

Senior Member
Joined
Feb 14, 2003
The memory is made by crucial, 2 512MB PC2700 DDR DIMMS.

MRD
 

Top Hat Theater

Member
Joined
Jul 24, 2002
Location
Lost in Thought
In my experience, Crucial has made great quality RAM albeit not the best of overclockers. It'll run tight timings at stock speed but the only way to find out if it's faulty is to run memtest.

~THT