VIA P4M800 Pro chipset: help me to choose RAM

[Peroxyde]

Hi,

I have an old Biostar motherboard which has the VIA P4M800 Pro
http://www.via.com.tw/en/products/chipsets/p4-series/p4m800_pro

The spec says:

Memory Support: DDR2 533/400, DDR 400/333/266
Max Memory: 2GB

I wonder how the same motherboard can accommodate both DDR and DDR2. But in my motherboard there are only 2 slots for DDR2 (I am certain because my old DDR modules cannot fit in).

Question1: Is it OK to use DDR2-800 (or faster)? Reason: In case this Motherboard dies, I can still use these RAM in other more recent computers.

Question 2: "Max Memory 2GB", does that mean "2 x 1GB" to fill the 2 slots or 1 x 2GB and the other slot must be empty?

And BTW why is the limit of 2 GB max? I have an even older computer which can accept 4 GB.

Thanks in advance for any help.

 

[tcsenter]

You can use DDR2-800 but in rare cases the BIOS might not know what to do with it based on the module SPD so you might need to set the memory parameters manually.

2GB Max means 2 x 1GB or 1 x 2GB, either one. Its limited at 2GB because you can't use DDR and DDR2 at the same time, thus limiting you to two DIMMs or modules.

 

[vailr]

I could be wrong, but I think 2GB sticks may not work. So, limited to a maximum size of 1GB sticks (and only 2 slots occupied), whether DDR or DDR2.
But like tcsenter said, not both memory types at the same time.
What CPU were you going to use? Be sure to double-check that the CPU is supported, first.

 

[Peroxyde]

Hi gentlement,

Thank you for your answers. This board only has two slots and physically, it can only receive DDR2 modules. May be the manufacturer had decided to opt only for DDR2 on this board.

So then I will try with 2 GB DDR-800 module to see how that go. I have a working computer with 2 x 2GB DDR2 modules. I can borrow these to test on that old motherboard.

What I am puzzled is that it has two slots, but the specs of the chipset says that it supports only 2 GB max. The board was manufactured in 2005/2006, why would they decide to put such a low limit in RAM?

 

[Lazlo Panaflex]

What I am puzzled is that it has two slots, but the specs of the chipset says that it supports only 2 GB max. The board was manufactured in 2005/2006, why would they decide to put such a low limit in RAM?

It's the VIA-imposed chipset limitation.

The Asrock VSTA series motherboards use the same chipset, and have the same 2GB limitation for the offical BIOS versions....but there are hacked BIOS that allow for 4GB.

 

[Peroxyde]

Answers after test with new RAM
- DDR2-800 (PC 6400) works OK. Tested with two different brands.

- Used 1 module of 2 GB DDR2-800 in 1 slot. Only 1 GB was recognized by the motherboard.

 

[tcsenter]

Used 1 module of 2 GB DDR2-800 in 1 slot. Only 1 GB was recognized by the motherboard.

This will be the case with 2GB modules that only have 8 chips total (all on one side) but 2GB modules that have 16 chips total (8 on each side) should be fine, subject to BIOS support.

The chipset can support 4GB, but the VIA specs assume a DDR and DDR2 'combo' implementation where only two memory slots can be used at the same time. If all four slots were the same type, it could support 4GB (but never be able to use it all due to addressing limits).

BTW, this chipset was just a respun P4M800, which was just a respun P4M533. IOW, the chipset design actually dates back to around 2002/2003. It only underwent minor revisions/improvements.

 

[Peroxyde]

Hi tcsenter,

Thank you for your expert explanation. I have little control on the RAM modules. I used two different brands of 2GB DDR2-800 modules, OCZ Platinum and Muskhin Redline. Each of them was recognized as 1 GB. I don't know how many chips they have because they are covered by a metal casing. But from the outside, I guess they have chips on both sides.

The only "issue" I have is that I can't find cheap DDR2 1GB module. Feel like a waste of money to refit an old computer.

 

[tcsenter]

WINTEC AMPO 2GB (2 x 1GB) 240-Pin DDR2 800

Mushkin Enhanced Essentials 2GB (2 x 1GB) 240-Pin DDR2 800

Crucial 2GB (2 x 1GB) 240-Pin DDR2 800