another stick of ddr not working

[RoseDragon83L]

I have an...

athlon xp1800+
512mb ddr 2100 ram (smart modular? or something else with smart)
msi k7t266pro2 mb
420w thermaltake ps

Last year I bought an additional gig of ram, 2x512mb of corsair ddr3200 cause it was cheap and thought I could use it in the near future for a new mb+cpu. I read around many forums and websites and all said it was ok to stick ddr3200 in a mb that ran ddr2100, it would just run at the 2100 speed not 3200, I was fine with that.
Stuck it in with the original 512 and would boot into winxp and could sit in windows if I did nothing, but would lock up soon after I tried to run things. Tried it in without the original 512 and still did the same, tried just 1 stick and the same. Tried different settings in the bios and same.
Now I have that gig of ram sitting on my shelf unused, ugh.
Bios settings allow cas2 or cas2.5, the corsair is cas2.5 at 2.5v (don't know if the voltage matters but the site lists voltage, I don't know how to check voltage for the mb).

Recently decided to try my luck again. Bought some rosewill ddr2100 (decided to try the 2100 just in case), also cas 2.5, timings on the site say 2.5-3-3 at 2.5v.
Put it in with the old 512 started booting up but before it even gets to the login screen it flashes blue really fast (can't see what it says) then to black. Tried changing the settings and removing the old stick of 512, same thing, goes black right before the login screen.



Am I just having bad luck with the ram I buy?
Am I unaware of some settings or something I need to change?
Is the motherboard I have just really bad with compatibility?
or.. Is there just a very very bad compatibility rate with ddr ram in general?

In my old computers I've had more than 10 sticks of sdram in 5 motherboards, yet never once had a problem.
Now I'm 1 for 3 in buying ram, only the first stick I ever bought worked.

[Panda Man]

I have an...

athlon xp1800+
512mb ddr 2100 ram (smart modular? or something else with smart)
msi k7t266pro2 mb
420w thermaltake ps

Last year I bought an additional gig of ram, 2x512mb of corsair ddr3200 cause it was cheap and thought I could use it in the near future for a new mb+cpu. I read around many forums and websites and all said it was ok to stick ddr3200 in a mb that ran ddr2100, it would just run at the 2100 speed not 3200, I was fine with that.
Stuck it in with the original 512 and would boot into winxp and could sit in windows if I did nothing, but would lock up soon after I tried to run things. Tried it in without the original 512 and still did the same, tried just 1 stick and the same. Tried different settings in the bios and same.
Now I have that gig of ram sitting on my shelf unused, ugh.
Bios settings allow cas2 or cas2.5, the corsair is cas2.5 at 2.5v (don't know if the voltage matters but the site lists voltage, I don't know how to check voltage for the mb).

Recently decided to try my luck again. Bought some rosewill ddr2100 (decided to try the 2100 just in case), also cas 2.5, timings on the site say 2.5-3-3 at 2.5v.
Put it in with the old 512 started booting up but before it even gets to the login screen it flashes blue really fast (can't see what it says) then to black. Tried changing the settings and removing the old stick of 512, same thing, goes black right before the login screen.



Am I just having bad luck with the ram I buy?
Am I unaware of some settings or something I need to change?
Is the motherboard I have just really bad with compatibility?
or.. Is there just a very very bad compatibility rate with ddr ram in general?

In my old computers I've had more than 10 sticks of sdram in 5 motherboards, yet never once had a problem.
Now I'm 1 for 3 in buying ram, only the first stick I ever bought worked.

there is no such thing as ddr3200 or ddr 2100 its called PC3200, whch is DDR400 I think you got it backwards, Motherboards that can use PC3200 can use PC2100. your MoBo can't handle PC3200, if it originally used 2100 I would assume that's the highest it can handle. Also, RAM isn't always compatable with other RAM just b/c they are both PC2100. You should always upgrade using the same RAM from the same company (or if you are sure it is compatable)

[RoseDragon83L]

there is no such thing as ddr3200 or ddr 2100 its called PC3200, whch is DDR400 I think you got it backwards, Motherboards that can use PC3200 can use PC2100. your MoBo can't handle PC3200, if it originally used 2100 I would assume that's the highest it can handle. Also, RAM isn't always compatable with other RAM just b/c they are both PC2100. You should always upgrade using the same RAM from the same company (or if you are sure it is compatable)

yeah yeah yeah, I been looking at too many numbers and lettering lately so I wrote it weird.

I am most certain that I don't have it backwards. You can run pc3200 in a computer that uses pc2100 as it is backwards compatible, it will just run as pc2100.

Though DDR memory was designed to be backward compatible (meaning you can use PC3200 DDR in a computer designed to use PC2100 DDR or vice-versa), we always recommend that you use the Crucial Memory Selector to find exactly the right memory for your computer. ...

Which is why I am wondering if it's something else I'm just missing here or if it's just bad compatibility with this mb since each of the corsair 2x512 and single stick of rosewill 512 won't run even without the original stick.

[Vivi]

yeah yeah yeah, I been looking at too many numbers and lettering lately so I wrote it weird.

I am most certain that I don't have it backwards. You can run pc3200 in a computer that uses pc2100 as it is backwards compatible, it will just run as pc2100.

Which is why I am wondering if it's something else I'm just missing here or if it's just bad compatibility with this mb since each of the corsair 2x512 and single stick of rosewill 512 won't run even without the original stick.

I think Panda is right, what happens is, if you have a board that can support PC3200, and stick say PC2700 in with the 3200 then it down clocks,

PC3200 doesnt work in a 2100mobo. I don't think.

also some mobos are VERY picky about Ram

[polobunny]

I think Panda is right, what happens is, if you have a board that can support PC3200, and stick say PC2700 in with the 3200 then it down clocks,

PC3200 doesnt work in a 2100mobo. I don't think.

also some mobos are VERY picky about Ram

This is false, yet true.
Most DDR400 sticks can run at 333mhz instead of 400, but they will not run at 266mhz. There's a limit to downclocking something you know.

Besides, it might just be your motherboard being picky, or simply not supporting the ram you put in it AKA DDR400.

[RoseDragon83L]

I think Panda is right, what happens is, if you have a board that can support PC3200, and stick say PC2700 in with the 3200 then it down clocks,

PC3200 doesnt work in a 2100mobo. I don't think.

also some mobos are VERY picky about Ram

just in case anyone else misses it...

Though DDR memory was designed to be backward compatible (meaning you can use PC3200 DDR in a computer designed to use PC2100 DDR or vice-versa), we always recommend that you use the Crucial Memory Selector to find exactly the right memory for your computer. ...

note, the parenthesis are not mine. That's from crucial's site, the manufacturers self titled as "The Memory Experts", lol.


but thanks for the replies so far. Anyone else have any ideas on this or am I just having bad compatibility issues.
Trying to decide if I want to send it back, keep trying sticks until one works, and just eat the restocking & shipping costs.

[RoseDragon83L]

This is false, yet true.
Most DDR400 sticks can run at 333mhz instead of 400, but they will not run at 266mhz. There's a limit to downclocking something you know.

Besides, it might just be your motherboard being picky, or simply not supporting the ram you put in it AKA DDR400.

ahh hmm, is there any way to tell for sure? I don't want to go through a bunch of other sticks to find out it's something on my end and not the fault of the memory or compatibility.

[polobunny]

Not really, check out your motherboard manufacturer site then your board specs so see if the ram you want to get is said compatible.

[Ahkei]

also some mobos are VERY picky about Ram

Especially AMD boards....



So yeah, I'd consult your mobo manufacturer's site, and check for compatibility, and if they don't list it, just shoot 'em an Email and ask.