What else is governing max memory supported?

[75below0]

Given the same CPU, motherboard chipset and # of DIMM slots, what accounts for differences in maximum memory supported by the mobo?

Wanting to buy an X48, but can only find max memory = 8 GB

To get to (Intel) max memory = 16 GB, have to find a SB = ICH10(R), currently only available with a P43/45 (no Nvidia please).

But I also see P43/45 + ICH10(R) with only max memory = 8 GB

So is it SB + Bios? SB + something physical on mobo (other than # DIMMs)?

 

[Lorne]

Its whats available in ram size when they designed the motherboard at the time, 2Gig sticks may have been the what was available at the time and filling 4 slots would give you 8Gigs.
If it supports 8 already Im sure memory remapping is presence and 16Gig wouldnt be a problem, Your OS would be the only other limiting factor and the number of available ramslots.

Im also not sure if 8Gig sticks are availlable in DDR2/3, Goodluck aquiring them if they are.

 

[DSF]

4 GB sticks were out before all P45 boards. That doesn't explain why some P45 boards are listed as 8GB max and some are listed as 16GB max. I don't think your reasoning is quite right there.

 

[Peter]

It isn't about the south bridge at all. It's about how big a single DRAM chip the northbridge can address. That limits the resulting size per rank (DIMM side). Count the DIMM slots, and there you are.

 

[VirtualLarry]

According to Intel's chipset docs, ALL P45 boards should support 16GB. I don't know why some are only listed as 8GB, perhaps they didn't undergo testing with 4GB DIMMs.

 

[Foxery]

4GB sticks are currently rare; some manufacturers simply didn't test them, so they don't certify/guarantee them.

As others have said, older boards may actually lack the ability to process the extra address space. They certainly didn't expect that any rational user would want so much when the products were released.

 

[75below0]

Originally posted by: Foxery
4GB sticks are currently rare; some manufacturers simply didn't test them, so they don't certify/guarantee them.

As others have said, older boards may actually lack the ability to process the extra address space. They certainly didn't expect that any rational user would want so much when the products were released.

LOL, it's for a build with an expected longevity of 6+ years. I believe that in ~4 years it will not only be desirable but affordable to quadruple my ram from 4GB to 16GB.

THANKS TO ALL FOR THE INPUT!

 

[piasabird]

The OS version is a limiting factor. Just because the Motherboard can use a lot of RAM, it does not mean the OS can efficiently use a lot of RAM.

Even if a motherboard has 4 banks of RAM slots, sometimes if you fill them all with high-speed low latency RAM, the motherboard may run slower.

 

[Foxery]

Originally posted by: 75below0
LOL, it's for a build with an expected longevity of 6+ years. I believe that in ~4 years it will not only be desirable but affordable to quadruple my ram from 4GB to 16GB.

Huh? No serious system lasts 6 years. Buying more RAM won't keep your motherboard and CPU from being hopelessly obselete. Spend half as much money on new systems every 3 years, and you'll wind up with a much better experience.

 

[tcsenter]

Originally posted by: VirtualLarry
According to Intel's chipset docs, ALL P45 boards should support 16GB.

According to Intel's chipset docs, all P45 chipsets support 16GB, not all P45 boards. Subtle but nonetheless relevant distinction.

 

[75below0]

Originally posted by: Foxery

Originally posted by: 75below0
LOL, it's for a build with an expected longevity of 6+ years. I believe that in ~4 years it will not only be desirable but affordable to quadruple my ram from 4GB to 16GB.

Huh? No serious system lasts 6 years. Buying more RAM won't keep your motherboard and CPU from being hopelessly obselete. Spend half as much money on new systems every 3 years, and you'll wind up with a much better experience.

Gee, you didn't even ask what kind of use it would be seeing. 3 years for me, 3 years for the kid (who obviously won't be playing the latest FPS at max settings), then off to the non-profit it goes. I assure you all parties will be happy with their user experience. "Hopelessly obselete" is a bit melodramatic - that Radeon 3850/512MB you've got in your rig...they make one for the 5.5 year old mobo I'm using now. I appreciate your well intentioned advice, I simply don't share your (long term) system requirements.

 

[75below0]

Originally posted by: tcsenter

Originally posted by: VirtualLarry
According to Intel's chipset docs, ALL P45 boards should support 16GB.

According to Intel's chipset docs, all P45 chipsets support 16GB, not all P45 boards. Subtle but nonetheless relevant distinction.

Hmm...now I feel a bit like I'm back at my original post...though as Foxery pointed out
"4GB sticks are currently rare{75below0 - and disgustingly cost prohibitive!}; some manufacturers simply didn't test them, so they don't certify/guarantee them."
Maybe if I go point out to the mobo manufacturers that they're making their P45s look better than their X48s...