New DDR2 SDRAM won't fit?!?

[PatrickGSR94]

My office machine is a Dell Precision 490 workstation with dual dual-core Xeon processors, and currently 4x 1GB sticks of PC2-4200 ECC fully buffered SDRAM. The motherboard has 8 slots, capable of 4GB each, for a maximum supported memory of 32GB.

Recently I got the Win7 x64 upgrade and 8x 2GB sticks of Crucial unbuffered DDR2 PC2-5300 SDRAM (4 packs of 2 sticks). According to memory.com, my machine can handle up to PC2-5300 memory, but all they offered for my system was ECC fully buffered memory, at around $90/GB. The memory I got from newegg.com was around $45/GB.

So I tried installing said memory today (Win7 x64 is already up and running on my original 4GB), and I found out that it PHYSICALLY DOES NOT FIT!!! The bottom edge of the PCB is actually narrower than the original ECC buffered sticks (looks like a notch on each end of the original, and none on the new) and the notch between the rows of pins is in a different location! I will post a picture to illustrate.

So what is the deal here? I thought PC2/DDR2 was the form-factor of the memory, and all PC2/DDR2 sticks would fit in any motherboard that would accept them. Do I HAVE to use ECC fully buffered memory in this machine?

 

[TheViper]

Buffered and unbuffered RAM have different notch locations.

See if you can send it back and either keep your current RAM or bit the money bullet for the faster buffered RAM.

 

[PatrickGSR94]

Well, it seems that the form factor is actually FB DIMM... wish I had known about that. That should probably be added to the Memory FAQ.

Newegg has FB DIMM's for about $65/GB. Not too much more. Hey it's the company's money.

I definitely need more than 4GB, since we're an architecture office running resource-intensive 3D design software. Since Win7 x64 uses more memory than XP x86 (I ASSume), I'm going to need that extra memory to make full use of having a 64-bit OS.

 

[TheViper]

Win7 does use more RAM than XP but not so much that 4 GB isn't enough for the OS.

Your 3D design applications though will definitely appreciate more RAM. When do they not, right?

 

[PatrickGSR94]

heh yeah, we were already having to use a "3GB switch" in XP x86 to allow programs to access 3GB of memory, while leaving less for the OS, to keep the program from crashing all the time. Unfortunately that caused problems in other areas. Looking forward to not having to mess with that anymore.

 

[4745454b]

Seeing as your rebuilding the machine, have you considered a bigger upgrade? Dual dual core Xeon sounds like your running an older netburst system. (not sure if they ever used FB Dimms...) If you are, and even if your not, a i7 9xx system with hyperthreading will be much faster. Its just company money right?

 

[jedimasterben]

Seeing as your rebuilding the machine, have you considered a bigger upgrade? Dual dual core Xeon sounds like your running an older netburst system. (not sure if they ever used FB Dimms...) If you are, and even if your not, a i7 9xx system with hyperthreading will be much faster. Its just company money right?

Nah, those Xeons are Core-based (5100 and 5300 series, according to the website). An i7 system (or Xeon W3500's) would be faster, but probably not fast enough for the price.

 

[PatrickGSR94]

Well just ordered 8x 2GB FB-DIMM's of Kingston DDR2-667 SDRAM today. Got the highest-rated ones on Newegg. Should be here later this week. Can't wait!