I have a asus p5vdc-mx motherboard and have upgraded from 2x512mb DDR1 RAM modules to 2x 1GB DDR2 Ram modules, however computer only see 512mb per module (to total 1GB). How do I fix this?

This board only supports DDR400 and DDR2-533

See this link:
http://dlsvr03.asus.com/pub/ASUS/mb/socket775/P5VDC-MX/E2545_P5VDC-MX.pdf

your board might not accept mixed memory try same i would go ddr1 since that is original setup

Update the BIOS

http://drivers.softpedia.com/get/BIOS/Asus/ASUS-P5VDC-MX-BIOS-0809.shtml

with rams, if the memory it has is higher than that of your cpu, the pc will not boot up or if it is too low compared to your cpu again.

thus, you say it has got two slots right, remove both of the 512's and insert the 1gig only, run your computer, i am sure it will boot up nicely. switch it off. put one 512, if it does not boot then you should know that your ram has an excess of memory that your cpu could not apprehend to.

post a coment if this does not work.

thanks,

wonder

Hi

You can add one more 1GB ram module.

Max Supported RAM 2 GB Memory Type DDR2Supported RAM Speeds 400 MHz · 266 MHz · 533 MHz · 333 MHz

this board supports only ddr1

The schematic layout of the P5VDC-MX on the user manual shows that there are 4 DIMM banks, set as 2 X 2 rows, 2 DDR2 and 2 DDR.

The user manual explicity states:


I am running different frequency modules without any problems. With the info above provided by ASUS, it may be possible that a fix could be available with a BIOS update. Otherwise, you can opt to use a lower capacity RAM along with your 1GB Corsair.

Hope this helps.

Your motherboard can take DDR or DDR2 RAM modules.

Crucial says: "Each memory slot can hold DDR PC2700,DDR PC3200,DDR2 PC2-5300 with a maximum of 1GB per slot." No sense getting 4GB since the max is 2GB.

You can get higher speed RAM (PC2-6400) because it is backward compatible.

I would go with the 2 X 1GB Corsair from the ones listed.

Or consider the options on Crucial's site. See this page:

http://www.crucial.com/store/listparts.aspx?model=P5VDC-MX

Two 1GB modules of DDR2 PC2-5300 run about $34 US.

(PS. Your 450W power supply will handle about anything.)

Your mobo is quite old and its chipset can only support a maximum of 512MB PER SIDE (technically called a bank) of a memory module. I would guess that your 1gb memory module has 8 chips that are all located on one side of the module, putting all of the 1 GB on one bank. Thus, only 512MB of your 1 gb RAM is detected and usable by your motherboard (the remaining 32 mb is most likely being used by your onboard video). You'll need to find a double sided 1 gb memory module (usually 8 chips on each side).

how can insttol the 2GB DDR2 667