Can I put 16GB in this HP system?

[cognus]

Guys I just took in a HP business class desktop dc5800 small form factor that has HP board 2820h with a Core 2 E8400. bios 01.51.
I want to max it on memory and install a Radeon card; it will do double duty as HTPC and lab mule [as conditions warrant]... and a bit of file serve on the side.
OS is Win7 Ultimate x64

the maybe twin brother of this system is better known I think: the HP dc7800; I have not determined yet if they have identical boards.
For each, there are some people claiming they were able to put 4x4gb in the system. the advertised max is 4x2GB.

I have 2 questions.. is the 16GB possible, and what is the best timing/speed part to use? crucial shows a generic part for the model since it can be equipped with a range of processors with diff FSB. this one presumably is 1333MHz

all advice Greatly appreciated

 

[cin19]

Only up to 8GB (4x2GB, 4 memory slots), for the dc5800, 4GB (2x2GB, 2 memory slots) for the dc7800.

Both do support non-ECC DDR2 PC2-5300 (667-MHz) and PC2-6400 (800-MHz) memory.

dc7800 http://h18000.www1.hp.com/products/quickspecs/12744_div/12744_div.HTML
dc5800 http://h10010.www1.hp.com/wwpc/ca/en/sm/WF06b/12132708-12132884-12132884-12132884-81559927-81560059-81804780.html?dnr=1

 

[cognus]

the 2x2 is for the ultra small form factor. the 'normal' sff, which I have, is 4 slot, two banks per channel

the problem with hp's spec is that to save documentation proliferation they give the lowest common denominator, as the same model .. i.e. dc7800 or dc5800, can come with a wide range of processors with wide range of fsb. same with the "memory finder" at crucial etc. none are specific to the model by processor. this I using Wolfdale @3ghz @1333MHz so I am thinking the sweet spot is ddr2 1066

 

[GhislainG]

DDR2-1066 16GB kits don't exist. Based on experience with other systems, I doubt your system could run 16GB at 1066MHz and you probably can't set it to anything higher than 800MHz.

 

[cognus]

quick read of the web is the bulk are running 10600 on E8400 - most ddr2 - some later mboards - ddr3. the default 800 mem runs at 6-6-6, bus clock reading 1330 per cpu/z
I can live with 8gb I guess, but will try to find the history of bios revisions

 

[GhislainG]

I have a 16GB kit at 5-5-5-15 and it's very stable (no application or system crash). Other systems with DDR2 8GB kits at 4-4-4-15 are relatively stable (a few application crash per year).

Can you set memory timings and voltage in the BIOS?