High Density SDRAM (256MB)

[daveleau]

How can I tell via markings if a RAM stick is HD or not? There are two types of 256MB SDRAM out there but I am not sure what is good and what is not for my BX chipset (older and does not support HD RAM)
Thanks
Dave

[Szech]

I don't know how to tell by looking... but if you put a stick of HD SDRAM in a board that doesn't support it, it will show up as half the amount it is supposed to be. So in your case, it would show up as 128 MB.

[DanU]

Finding the density is surprisingly easy. No need to look up part numbers. Just divide the amount of ram by the number of chips on the DIMM. e.g. a 256MB (2Gbits) DIMM with 4 chips will be using high density 64MB (512Mbits) chips. A same sized DIMM with 8 or 16 chips will use lower-density 32MB (256Mbits) or 16MB (128Mbits) chips.

I think the problem is with using DIMMS based on the 64MB (512Mbits) chips. If that's the case, 512MB DIMMS using 8 chips or 256MB DIMMS using 4 chips will cause problems.

[This message has been edited by DanU (edited 05-24-2001).]

[daveleau]

Ok, here are the stickers from the ram, they should tell.
SpecTek
P32M6416YLEB7- 133CL3A
0199 M1/N29555 YN

32X64 PC133/12

Does this mean these are 64MB or 32MB ships. There are 8 chips. I can tell it is PC133 CL3.
Thanks
Dave

[RobRich]

Take Intel i440BX, the highest density is 128 MBit per chip, 128 MByte per row, and even those only work when the row is formed by eight chips, each 8 bits wide to form 64 data bits in parallel.

This means a 128 MByte DIMM would have to be 8x64 to work, and a 256 MByte would have to be 2x8x64 (two sides aka rows 8 chips each).

http://www.sysopt.com/forum/Forum5/HTML/004445.html

Hope this helps,
Robert Richmond

[daveleau]

lol, I love how I even bookmarked it at the end so I could find it again. lmao. Thanks. I deem this a high density chip then and it will not work in my system. http://www.sysopt.com/forum/frown.gif
Thanks
Dave

RobRich,
Did not realize you were in Chattanooga. My fiance is from there and her dad heads up the Special Olympics there. Nice area. I have been up quite a few times.

[This message has been edited by daveleau (edited 05-24-2001).]

[Richard_Cranium72]

Dave, you mean my old Packard Bell 1030 mobo in a NEC will support the HD chips and the BX board will not ?

I'd thought this old board would have been a Fossil too, maybe not..

[RobRich]

I figured you had forgot the bookmark. http://www.sysopt.com/forum/wink.gif

I keep that post link in my fav's, because you wouldn't believe how many people send me questions about HD memory. Makes for a quick response.

About Chat-town, I love it here in southeast TN. I actually live about 20 miles east of Chattanooga (http://chattanooga.about.com) in Cleveland. The area offers many great features: mountains, rivers, lakes, fresh air, etc. http://www.sysopt.com/forum/smile.gif

Robert Richmond

[This message has been edited by RobRich (edited 05-24-2001).]

[daveleau]

Oh well, nothing like trying to tell you yea or nay. It works fine in my BF6...

Thanks
Dave

[DanU]

Thanks for the link RobRich. I didn't realize that 32Mx4bit chips could cause problems.

These memory type/density incompatibilities are going to make my head spin...