Can I run pc100 and pc 133 together?

[Bizkitkid2001]

I found a stick of 64mb PC100 SD-RAM. I think its PC100 because it was made about 2 years ago.(Model #- M5M4V64S30ATP) I put it in my system, which already has 256 MB of PC133 SD-RAM and everything ran smoothly. It registered in Windows as 320Mb of system ram and everything seemed right. Is it ok to run this memory at 133MHz instead of 100? Will it burn out or will it hurt my system?

System specs
1.2Ghz amd thunderbird(133MHz)
40WD 7200 RPM drive
WindowsXP
IWILL KK266+

THanks,
BiZkItKiD2001

[Midknyte]

some motherboards will autodetect the ram and slow your system down accordingly. I know some HPs did that. Instead of getting 133, you're really getting 100 for all ram.

If you are running at 133 for all the ram, you might get weird errors since you are in essence overclocking your ram.

[Bizkitkid2001]

My system didn't downclaock all my ram to 100, just made that one stick of ram 133. What kind of erros will I get?

[Midknyte]

It's hard to say. You might get blue screens or lockups. You know, the normal overclocking crashes. If it's running ok, then I wouldn't worry too much.

[grimfandango]

yea You can use pc 100/pc133 together as long as the FSB or the cpu is running at 100mhz!!


:)

[Bizkitkid2001]

But my FSB is running at 133mhz

[Midknyte]

Some boards can run 133FSB, but run the ram at 100 async. You might want to double-check that. I don't think it's worth the extra 64mb if it slows down your ram to 100.

[bushmaster]

It's gonna default to the slower speed.

[BigBlue66]

Not sure I agree with what's been posted. Yeah, I always heard that the system will run all memory at the speed of the slowest stick.

However, it could be possible that the PC100 is indeed being overclocked to PC133 speeds. I have no empirical evidence with which to base that idea on, but it seems to make sense.

If the PC100 could not be overclocked to 133, then most likely the system wouldn't even boot.

Keep in mind, too, that the rated speed of a memory stick is the speed it's guaranteed to run at, but it might run faster than that.

It takes high quality RAM to overclock like that, and the worst case scenario is that the RAM will not last as long and also run hotter.

[Bizkitkid2001]

How can I tell if my ram is running at 100mhz? My cpu is still running at 1.2ghz. It didn't loose any speed. And my games still run as fast, some games got about a 5 FPS increase

THe brand of the 64MB of memory is Mistubishi

[gregorian]

since you say that your FSB is at 133MHz, and that your ram also runs at 133, then you are indeed overclocking your pc100 RAM. but dont worry, the worst that could go wrong is that it will fuse/burn and you com will hang. after you restart, your com may not even POST(self-test). all you have to do then is remove the damaged ram and throw it away!

[Bizkitkid2001]

Well last night I played MOHAA, Flight Simulator 2002, and Battle field 1942 for a good 4 hours with this stick of PC100 in my computer and I got no lock up or freezes or no BSODs.

Does Mistubishi still make memory? Because I am buying my memory from them next time:cool: