abit bh6 sees 256mb ram as 128mb pls help

[yaputzis]

my system:

abit bh6 with latest bios "ss"
celeron 700mhz
win2k pro

i've just installed a stick 256mb ram but my motherboard recognizes it as 128mb. what should i do solve this?

any help appreciated

thanks

[Buji]

If you are using more than 1 stick, put the highest capacity into the lowest # slot, although the Abit Manual says position doesn't matter. The stick might also need to be taken out and reseated. I recently installed a second stick of 64 in my BH6 and it was not recognized either at first. Simply taking it out and reseating it cleared it up. I'm using Bios QM.

[Peter M]

There are 256-MByte DIMM sticks that ol' i440BX chip can't handle.

These look (physically) double-sided but aren't (logically), and use 256-MBit-per-chip technology which is beyond reach for the memory controller in the i440BX.

Solution: If you want to use 256-MByte sticks, you must use true double-sided ones that logically form two rows of eight chips, each 128-MBit by eight bits - not those modern ones that form one row of sixteen chips, each 256-MBit by four bits.

The hard part will certainly be to explain to the store airhead that you need a 2x8x128x8 DIMM instead of the 1x16x256x4, and then to identify one ... a safe and easy method would be to get a 256-MByte DIMM that uses the same type of chip on both sides as does a single-sided 128-MByte one. Then you have 128x8 chip technology for sure.

Regards, Peter

[Buji]

More info here: http://www.zepa.net/hypermail/elug/hardware/2001/01/0021.html http://www.zepa.net/hypermail/elug/hardware/2001/01/0026.html
According to my Abit manual there is no mention of having to use registered dimms at 256mb.

[chiller]

i have a BH6 bios (sp) 850 PIII i have 512 megs of pc.133 in it two 128's and a 256 all from crucial works great

[Buji]

Chiller. I don't know if you noticed, but the Crucial Memory Selector doesn't even list 256dimms although my manual says it supports it. Could you please post the model# of your 256 stick? Thanks. http://www.sysopt.com/forum/smile.gif

[Nighthawk]

The DIMM you have is a "32x4" DIMM, designed specifically for VIA chipsets (each chip is 16mb, but it's addressed differently.

The kind you need is 32x64 (or 64x32, I can't remember which). Each chip is still 16mb, but it's addressed in a way that BX boards can handle.

[Peter M]

Exactly, as I said - the non-BX-compatible DIMMs use chips that are 4 bits wide each. You need 16 of those to form one single row of memory (which is 64 bits wide on a DIMM). Meaning you have chips on both sides of the DIMM, but only one logical "side" that is twice the size as what you'd get if you'd used the same number of 8-bit-wide chips of the same size and form two logical sides.

These RAMs are far from being "specifically designed for VIA chipsets" - it's just that the DRAM controllers in ol' i440BX and crippled i810/i815 can't handle them.

Regards, Peter

[RalphArch]

you can even get 256 of that 256MB PC133 32x4
for $47
http://64.225.254.190/ShopSite/page60.html