Can my MacPro use the old DDR ram?

[icyx]

I'm current only a Mac Pro 2GHz with 1 GB of ram. the Ram is DDR FB-DIMM 667MHz, the problem is that it's only 1GB. I just switched to this Mac because the older one i had was a older duo instead of this Quad.

Now i'm wondering if i could replace the 2x512 DDR2 667MHz ram and put in the older DDR SDRAM PC3200U-30330.

The only reason is because i have 4 gigs of the older one, and even using the older mac it felt a bit faster working than i get with the lagg of 1gb on the new mac.

[Nicoya]

No, you can't. The RAM sticks are physically different so they wouldn't even fit. DDR2 RAM is very cheap nowadays. You can get 4 gigs within $50 - $60 if you shop online. I recommend Newegg or Mwave.

[icyx]

4gigs for $50-60? i can't seem to find those. do any DDR2 667mhz fit?

[Nicoya]

I found this $50 4 Gig set (2x 2GB) - Newegg.com - G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 &#40C2 6400) Dual Channel Kit Desktop Memory - Desktop Memory

I didn't do a intense search so there may be some better but this is DDR2 at 800 which is faster but will work and run at 667 on your mac pro just fine.