memory compatability

[Christo]

just been reading a thread someone posted about old PC100 and PC133 ram and
mixing pc100 with pc133 will cause crashes and blue screens.

is the same applied to newer ram for instance

on a dual channel board

ddr266 pc2100 512mb x2 cl2 (on one channel)

and

ddr333 pc2700 cl3 (on the other channel, seperate from the other stuff)

i have been getting IRQL_NOT_LESSOR_EQUAL

bue screen

memory problem,

is it related?

would appreciate any help whatsoever

 

[DaveW]

You are ALWAYS better off not mixing memory.

 

[Alceryes]

Newer DDR systems are much more lenient about mixing RAM. As long as you are
running the memory at ddr266 (and NOT trying to run it in dual channel mode)
you *should* be OK.
This isn't always the case though. An easy way to test would be to pull one
of the sticks and run it for a few days to see if your problems clear up.

 

[kony]

just been reading a thread someone posted about old PC100 and PC133 ram and
mixing pc100 with pc133 will cause crashes and blue screens.

Take all info gleaned from newsgroups with a grain of
salt... in general, it isn't true.
Many times I've mixed memory, very seldom a problem...
usually the problem is filling all slots and trying to run
at max memory bux supported by the board, not mixing two
modules and running at 100MHz (since the PC100 is the
limiter).

is the same applied to newer ram for instance

on a dual channel board

ddr266 pc2100 512mb x2 cl2 (on one channel)

and

ddr333 pc2700 cl3 (on the other channel, seperate from the other stuff)

No, the system should run at the speed of the lowest
denominator, that is, PC2100 speed and whichever timings are
lowest at that speed for _either_ module.

i have been getting IRQL_NOT_LESSOR_EQUAL

bue screen

memory problem,

is it related?

would appreciate any help whatsoever

There should be another part to the message, a number like
"0x000000(n)". Take that number and head over to
microsoft's 'site... often it's a driver problem.

When in doubt about memory integrity, run
http://www.memtest86.com for a few hours.

 

[Skeleton Man]

just been reading a thread someone posted about old PC100 and PC133 ram and

mixing pc100 with pc133 will cause crashes and blue screens.

That was probably me.. I said it *may* cause crashes and blue screens..
it's unpredictable.. my personal experience was that every so often, at
random times windows 2000 would crash with IRQL_NOT_LESS_OR_EQUAL.. it
wouldn't do it every time, some days I could run for hours before it
happened, other times it would crash within minutes.. I took out the PC100
stick and replaced with 133 and it all ran fine.. (running memtest86
verified the ram was not faulty either)

is the same applied to newer ram for instance

yes, but the only way to see if your problem is caused by mixing ram, is to
run the PC with just one of the sticks of ram for a while.. and see what
happens.. they change it over with the other and try once more..

Regards,
Chris

 

[Christo]

currently running with dual channel on and everything is ok apart from this
IRQL error, also, the memory is going to the slowest memory, ddr266 and not
the 333 i have installed on the other channel.

why cant i run it in dual channel, isnt dual channel kinda like having a
whole different channel for that DIMM slot? that isnt related to the other
two slots?

thanks for the advice though, ill try removing the two cheap ddr266 and see
if the crucial ddr333 will be cool on its own.

 

[Alceryes]

Dual channel mode requires 'almost' identical sticks of memory to be
installed (chip type/count, bus speed, and latency) . If you have 2, DDR266
sticks and 1, DDR333 you are definitely 'not' running in dual channel mode.
If you have 2 of both types then that is probably the reason for your BSOD's
since they are different chips.

 

[kony]

Dual channel mode requires 'almost' identical sticks of memory to be
installed (chip type/count, bus speed, and latency) . If you have 2, DDR266
sticks and 1, DDR333 you are definitely 'not' running in dual channel mode.
If you have 2 of both types then that is probably the reason for your BSOD's
since they are different chips.

Unless I overlooked specific mention of the system, we can't
assume dual channel requires same memory, or even remotely
similar modules... often it doesn't even require same size
modules.

 

[Gareth Tuckwell]

just been reading a thread someone posted about old PC100 and PC133 ram
and mixing pc100 with pc133 will cause crashes and blue screens.

Only if you try to run slower memory at higher speeds??

is the same applied to newer ram for instance

I don't think so.

on a dual channel board

ddr266 pc2100 512mb x2 cl2 (on one channel)

and

ddr333 pc2700 cl3 (on the other channel, seperate from the other stuff)

i have been getting IRQL_NOT_LESSOR_EQUAL

I would have thought that you can mix and match any *speed* of memory. The
PC will only be guaranteed stable at the lowest speed rating, of course. So
pc133 memory can be run at the slower pc100 speed, but pc100 probably could
not manage 133! However, that is now the whole story: With DDR, mixing
memory of different CAS timings is a different issue. This is the cl number.
Normal RAM is cl2.5, fast (expensive) gaming RAM is cl2 and cheap windows
memory is cl3. I don't know exactly what this number is for, but I think it
is something to do with refreshing the charge in the RAM - how quickly it
can respond to requests for info. The DDR rating is how fast it can pump
data up and down the bus. You have mixed cl2 and cl3 here and I presume that
is why the computer is complaining - it can't refresh the memory properly.
If you are running these memory modules at 266 (133MHz), then the speed is
not a problem.