I Recently bought some memory from Ebay. After doing all checks to find what type of ram I needed, I found that my mobo- Intel D815EGEW can take a max 512mb Unbuffered Non ECC 168pin SDRam Single or Double Sided Memory. So after watching many auctions on Ebay I finally decided to buy what I thought was a good deal- an ATA 512mb double sided stick which matched the rest of my requirements.When I fitted it and powered up my PC all I got was 3 short error beeps.After trying in both of the 2 ram slots on my board and checking I fitted it correctly I decided to try in my other PC a K6XV3+/66 Mobo. In this system it only showed as 128mb! Can anybody shed some light on this or have I been ripped off!! Thanks

Although you can use 512MB it has to be 2 X 256MB.

The Intel® Desktop Board D815EGEW has slots for two 168-pin unbuffered Dual Inline Memory Modules (DIMMs). The Desktop Board D815EGEW can support a minimum system memory configuration of 32 MB and a maximum system memory configuration of 512 MB. A minimum of 64 MB of system memory is recommended. The Desktop Board D815EGEW supports DIMM sizes of 32 MB, 64 MB or 128 MB with 64-Mbit device technology and 256-MB DIMMs built with 128-Mbit or 256-Mbit device technology.

http://www.intel.com/support/motherb...013163.htm#9.0


On further review you do need SDRAM max 2 X 256MB. And most likely 100MHz although 133MHz is possible depending on your Processor.

Are there specific requirements for using 133 MHz SDRAM memory?
Yes. All of the following conditions must be met for the memory to operate at 133 MHz speed:
An Intel Pentium III processor with 133 MHz system bus speed must be used
All memory must be 133 MHz speed.
All memory must have properly programmed Serial Presence Detect (SPD) data
No more than four rows of 133 MHz SDRAM should be used. Four rows would be two double-sided DIMMs, or one double-sided DIMM and two single sided DIMMs.
If a 66 or 100 MHz system bus frequency processor is used then the memory will run at 100 MHz. If memory speeds of 100 and 133 MHz are mixed, then all memory will operate at 100 MHz. If more than four rows of memory is used then all memory will operate at 100 MHz

What is PC133 and when can it be used?
PC133 is a specification for SDRAM that is similar to PC100 except the memory is capable of running at 133 MHz rather than 100 MHz. It will provide higher performance when using a processor with a 133-MHz system bus. If PC133 SDRAM memory is integrated in a system featuring a processor running at 100-MHz system bus the memory will only operate at 100 MHz.

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Hi, and thanks for your reply Jephree.
Well my processor is a P3 1gig with 133Mhz speed and CMTL (Computor Test Labs) seem to have tested many 512mb dimms with my make of board! (Although not the ATA dimm I have!!)

http://www.cmtlabs.com/mbSearchResul...oSubmit=Search

Also what is density?- is it 64Mx64?? And any ideas why a 512mb stick would only show as 128mb?

I see the test results but am confused as well as Intel states specifically no more that 256 on individual sticks

What is RAM Density?

http://www.fica.com/site/html/servic...c_id=240000963


This is a very common issue using modern RAM on an old motherboard.


As to this RAM on the other computer the only thing that stands out here is the specs:

System Memory

16 MB TO 384mb MEMORY USING UNBUFFERED dimms
Three 168-pin DIMM sockets using x64 SDRAM, 3.3V
PC-100 SDRAM DIMM for 100MHz external system bus clock processors
ECC supported (uses x72 C SDRAM DIMM)

http://www.itox.com/pages/products/m...almb/K6xV3.php

The voltage; the speed; the size and most likely the density are all off the spec.