a question about DDR3 1333/1066

[alex2020]

Dear forum,

My motherboard has 4 slots of DDR3 1333/1066, with maximal 16 GB.
http://www.findlaptopdriver.com/specs-hewlett-packard-3647h/
I currently have two 4 GB and I want to increase to total of 16Gb.
I have two questions:
1. Can I add one 8B memory stick, so that I have 2x4GB + 1x8Gb? Will this work ?
2. If answer to [1] is positive, should the speed of the 8GB stick be the same as of 2x4Gb ?

Thank you!

 

[bluestang]

Do you have a SSD for your OS drive? If not, don't bother with more RAM. If you do then 2x4GB instead of a single 8GB since the RAM runs in dual channel and that MB only supports 4GB sticks anyway. And keep the new RAM the same speed as your existing RAM

 

[70 Polara]

Seeing as that's an old LGA775 board (I recall working on a few of those HP 8000 series systems long ago), I doubt it will be able to "see" any 8GB DIMMs at all. I also recall some literature stating the Q45 chipset would work with 16GB of DDR2 but only 8GB of DDR3 memory.....

So there is a real possibility that even if you got two more 2Rx8 low density DIMMS in either 1066/1333 speeds, the board may not work with them at all. Though with some quick searching I see evidence that some people did manage to get 16GB working in those systems, but had to try different brands of memory to find something that would work.

I agree with bluestang, I'd upgrade to an SSD first if you don't have one. Or look for an old and cheap system with at least a 2nd/3rd gen Core i5/i7 instead. Optiplex 790/990 and 7010/9010 systems can be had for next to nothing these days and would be a very nice budget upgrade over anything Core 2 based.

I picked up a new looking Optiplex 790 MT for a family member off craigslist a few months ago for $100 and it had an i7 2600 CPU, 16GB of memory, a GTX 750 video card, and a 256GB SSD........

 

[kirbyrj]

I would say, no, you can't just add a 1x8GB DIMM. If anything, I would find 2x4GB of whatever speed you're running now and add it that way. First, you're better off for compatibility, and second, you still have dual channel memory.