16GB limit

[pitz]

M4A78T-E motherboard here. Asus says it is limited to 16gb RAM (4 x 4gb DIMMS), which doesn't seem like a lot for what I use it for and intend to use it for.

Is this 16gb limit just what they've tested (because >4gb DDR3 DIMMS are very rare and expensive)? Or is it a bona fide limit due to something electrical?

When/if 8gb DDR3 DIMMS become available (and affordable), is there likely to be any issue with upgrading to 32gb RAM?

 

[Fayd]

if you want a higher limit, go with a server motherboard.

surely the price of a server motherboard is a drop in the bucket compared to the sticks of ram...

 

[tcsenter]

By the time 8GB DDR3 modules are "affordable", you'll have already upgraded to something else, or will want to.

 

[ViRGE]

Bear in mind depending on what OS you use, you may be limited to 16GB anyhow. Vista/7 Home Premium has a 16GB cap.

 

[StrangerGuy]

I'll say it will take at least another 5 years for 16GB to become mainstream.

 

[VirtualLarry]

As far as I know, it's a limitation of the memory controller. Which begs the question. If that's an AMD mobo (I assume), then the memory controller is in the CPU. And as far as I know, they support something like a 40-bit memory address space. So one would think that perhaps they wouldn't be limited to 4GB DIMMs. Except, the mobo needs to have enough traces to the RAM slots to accomidate the number of lines necessary, so the mobo may indeed be limited to 4GB DIMMs.

Are 8GB DIMMs even on the market, for desktop systems? I haven't seen any myself. I know that Intel 775 mobos (with the memory controller integrated into the chipset), are indeed limited to 4GB DIMMs (P45), and 2GB DIMMs (P35, X38/X48).

 

[ViRGE]

Are 8GB DIMMs even on the market, for desktop systems? I haven't seen any myself. I know that Intel 775 mobos (with the memory controller integrated into the chipset), are indeed limited to 4GB DIMMs (P45), and 2GB DIMMs (P35, X38/X48).

Nope. The only 8GB DIMMs I've seen are ECC + Registered for server use. They also cost several hundred dollars per DIMM.

 

[Emulex]

use ssd as a bridge for now - max out on 4gb sticks and use SSD for everything else.

or get a xeon motherboard they have 6 slots per socket. sweet spot for best mhz is 12 x 4gb = 48gb with dual socket setup for cost. then add a few ssd's

 

[tcsenter]

Any recent AMD64 revision CPU (Rev. F and later for AM2) should be able to support 32GB, according to the information I've seen. Chipset can still impose limits on MAX DRAM decoding and remapping support. But there won't be any 8GB unbuffered DIMMs for a while, and the BIOS will need to know how to handle them when they come available.

 

[wwswimming]

Nope. The only 8GB DIMMs I've seen are ECC + Registered for server use. They also cost several hundred dollars per DIMM.

on my first CAD workstation we paid $500 a Megabyte.

several hundred $ for 8 GB of RAM is a dream come true.

not that i'm complaining about buying 2 x 2 GB DDR2 for $100.

 

[Billb2]

LOL, 4 x 4gig.
Wouldn't it be cheaper to buy 100 Pentium 4 towers and make your own cluster?

 

[Fox5]

LOL, 4 x 4gig.
Wouldn't it be cheaper to buy 100 Pentium 4 towers and make your own cluster?

No.

 

[tcsenter]

Samsung reportedly is sampling 4-Gbit DDR3 DRAM that can be used to create 8GB unbuffered modules. So I would expect them to be available in a three to six month time-frame, and at an obscene price for the first few months.

 

[Stefan Payne]

If there were unbuffered DDR-3 SDRAM DIMMs with more than 4GiB/DIMM, it should work with an AMD CPU.

But since that's not the case, you can't use more than 16GiB with an existing AM3 Board.