RAM limits for N-Alvorix-RS880-uATX (HP p6650z)

[prr]

I just got the p6650z--4 gigs of RAM. It has 4 slots, and there are 2 sticks of 2 gigs each, currently. If I'm reading the motherboard specs right ( http://support.hp.com/us-en/document/c02560084), it looks like it can take up to 8 gigs of RAM (for 64-bit OS), and can handle 4 gigs in each slot.

And so, staying with the 2 2-gig sticks, I could insert two more 2-gig sticks, or one more 4-gig stick, but NOT 2 more 4-gig sticks? I'm not a RAM expert by any means, but I'm just surprised that a mobo could handle 4 gigs of ram in one slot, but not in a second slot. 

Or am I misunderstanding something in that spec sheet?

[Hanspuppa]

Hello prr, I don't know much about memory either. It appears that HP does not as well.

Here  is a link to the HP web site that shows your motherboard. It shows in the image of this board to have 4 memory slots, but in the description, it shows only 2 slots available.

Here  is a link for your product that shows this system can support 16 GBs of memory.

From what I have read about some of these HP systems, many that try to use more than 8-9 GBs of memory seem to have some issues.

If you currently have 2x2GB modules installed, I would suggest adding 2x2GB modules for a total of 8GBs.

It is recommended to install memory modules in pairs for best performance.

Since the specifications show your system will support both 1333 mhz and 1066 mhz memory, I would determine what speed your memory is and purchase that speed, in order to match your existing memory speed.

If you check your memory modules, they will most likely will be, or should be, installed in the different channels, either blue or black. Any new modules should be installed in this manner as well for best performance.

I have 9GBs total and never use more than 3GBs, so any above that is essentially not used, and a waste of money for my purposes. There are some users that can benefit from more memory depending on the applications they use.

I would go to some memory vendors and perform the Memory Configurator and let them determine what memory is compatible with your system, rather than just purchasing some memory of the same type and speed.  These non-specific modules may not work in your system due to timing differences.

Hope this helps.

[wb2001]

There are 2 different and distinct MOBO used in that computer.

prr stated:  N-Alvorix-RS880-uATX (Alvorix)

The N-Alvorix-RS880-uATX (Alvorix) MOBO is limited to 8GB.

The H-ALVORIX_HF-RS880-uATX MOBO is limited to 16GB.

This is a dual channel config, pairs A and B.  Each pair has 2 banks. Each pair must be matching.  All must be same speed.

http://en.wikipedia.org/wiki/Dual-channel_architecture

[prr]

Thanks for the replies.

OK wb2001, what you are saying is that, when upgrading my RAM, I should NOT use a single 4-gig stick, but two 2-gig sticks, for my configuration---correct?

[wb2001 · Accepted solution]

Yes, because:

Your computer uses only dual channel memory, configured as pairs A and B.  Each pair has 2 banks. Each pair must be matching.  If your MOBO is the  N-Alvorix-RS880-uATX (Alvorix) you are limited to 8GB max. You said  two 2GB were installed. You could add another two 2GB of the same speed. That would max out your "N" board.  I see no need to purchase two 4GB, and toss away the installed pair of two 2GB modules. I hope that is clear to you, now.

The N-Alvorix-RS880-uATX (Alvorix) MOBO is limited to 8GB.

The H-ALVORIX_HF-RS880-uATX MOBO is limited to 16GB.

[mikezachlowe200]

Hello,

That is incorrect.  I have the same mother board and when i bought it it came with 2 x 2GB DDR3 ram and 1 x 1GB DDR3 ram (a total of 5GB DDR3 ram).  The computer runs great.  This clears the confussion of being able to just use 1 slot.  I have 4 slots and 3 are filled.  This is how it came when i bought it.  So, yes you can just use 1 single ram in the paired slots. 

Hope this helps.

IronMikeAce

[morganfair]

as stated that board will accept 8g at 32 bit or 16g at 64 bit. so a 64 bit system will accept 4 of 4g memory sticks. if you have diffrent size memory sticks put the highest g stick in the slot toward the FRONT of the computer. that is to say if you have blue and white memory slots like mine put the highest g in the white slot. hope this is some help.

[Elliott-P]

The HP Motherboard Specifications under memory upgrade information list it as Dual channel memory architecture.

Their Upgrading Memory (RAM) state that for Windows 7 Editions to operate in dual channel mode all DIMMS must be of the same density & same chip technology (x8 or x16).

I read all this to mean I can add two additional memory moduals (4 gb each) and have a total of 12 gb of memory. But I will not get dual channel? If so would I be better off replacing the two 2 gb modules with the two new 4 gb modules?

Has anyone had experience with this?

[watchtower]

That information was incorrect. Your Motherboard will accept up to 4Gb per slot (16Gb Max.) on 64bit system.  On a 32bit system 8Gb's is the Max. You do not have to use dual channel,But it is suppoed to be smoother and faster.According to what I've read it just means the modules are the same size (GB) speed (Mhz) and Latency (timming).

[Woodwood]

My reading of the specification of this motherboard N-Alvorix-RS880-uATX (Alvorix) - so that there can be no doubt of what I am referring to it is -

http://support.hp.com/us-en/document/c02560084

is essentially that for a 64-bit OS it can use 16GB and for a 32-bit OS it can use up to 4GB (but you usually able to use the full 4GB) [expanded from 'memory upgrade information']

Also, it might be useful to read Big Dave's post on memory for this m/b in http://h30434.www3.hp.com/t5/Desktop-Hardware/Upgrading-Memory/m-p/1068519#M40677, p41

Woodwood

2.December.2011