Is DDR RAM PC3200 backwards compatible with PC 2100?

[alenhard]

First I have to admit that I'm a dummy when it comes to RAM.

On my current desktop setup I've got a year-old MSI 845 Ultra ARU mobo and 512MB DDR PC 2100 RAM at 266mhz.

I'm wanting to kick it up to 1 GB of RAM but now there appears to be memory that is more powerful.

Two questions:

1) Would DDR RAM PC 3200 be okay to use with the PC 2100 stuff, or should I not mix the two?

2) Can RAM be compatible at different frequencies- for example, a stick at 266mhz and another at 400mhz?

[g_shocker182]

Chances are it won't fit.

I once tried to jam a pc133 stick of ram into a pc2100 socket. Bad idea.

[gmatov]

No, they can't be compatible, if you mean will one run at one speed while the other runs at the other.

Just as PC100 and PC133 would default to the slower speed, if your board will even support PC3200 (many won't ), it would most definitely slow down to the PC2100 rate.

Many mobos, you know, require matched DDR, and have only been approved for use with particular, tested, DDR. Look in the manual to see what yours will work with. I have not yet found ANY DDR that will work with my only dual RAM machine, so it's still using PC133.

Shocker,

Yeah, it will fit, mechanically. All types are made to the standard archutecture for that type of module.

How could you even try to jam a 168 pin module into a 184 pin slot? With 2 orientation keys, rather than 1? Physically, totally different. Did you get any sparks or smoke?

Gonna have to start reading the manual a little more faithfully.

Cheers,

George

[Solarjetman]

You will not see any performace increase with PC3200. All RAM sticks in a computer will slow down to the speed of the slowest stick.

[SquirrelDip]

If your motherboard is currently using PC2100 DDR RAM then you should be able to use the PC3200 DDR. As Solarjetman points out, you will see no speed advantage going to the new RAM.

If you are planning to upgrade to a new motherboard in the near future then the advantage will be that you can use the PC3200 on the new motherboard. If it's going to be a while till you upgrade then save your money and buy the cheapest you can find (probably PC2100, maybe a little faster).

If you're concerned about the RAM then take your computer to the shop and try the faster RAM - it's been my experience that most shops won't have a problem with this because your trying to buy the more expensive RAM (if they do have a problem then find another shop).

[g_shocker182]

Shocker,

Yeah, it will fit, mechanically. All types are made to the standard archutecture for that type of module.

How could you even try to jam a 168 pin module into a 184 pin slot? With 2 orientation keys, rather than 1? Physically, totally different. Did you get any sparks or smoke?

Gonna have to start reading the manual a little more faithfully.

George,

This happened a long time ago, in a galaxy far, far, away.

[alenhard]

Thanks for all of your replies. I think you've helped me understand my options a lot better.

@SquirrelDip-
Upgrading the mobo in the near future was actually the main reason I was asking, so thanks for the clarification. Also, Premiere Pro is on its way this week and I want the system to be up to speed!

[RabidDog]

I asked similar question of crucial (using pc2700 with pc2100) and they said yes it should be ok, but it will work at the slower speed. HA! tried my existing ram at 166mhz and it works fine. I think it was shipped with the wrong speed set (133 x 166).