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6GB Installed Memory, only 3GB usable
I have a Optiplex 755 and just bought two of these: http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=A6993648&mfgpid=192262
I verified these were listed for the type of computer I have and that it could accept more memory before buying.
It came with two sticks of Kingston 1GB installed, these are still in the computer but I moved them to DIMM slots 2 and 4 and installed the new 2GB sticks in slots 1 and 3.
I've read several posts on here and other websites that say to try a number of different things.
Wondering what I should try first though.
Note: I have no experience with BIOS, and using Win 8
speedstep
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May 13th, 2015 10:00
"Also it has been my experience that installing a video card will always recover the shared buffer for use as system RAM. "
https://support.microsoft.com/en-us/kb/978610
This is wrong for this system and other Optiplex/Dimension systems etc. PCI-E shared ram chipsets Do not allow recovery of Shared ram EVER. 4GIGS is the Limit for 32 bit Windows.
Thats why in in the Optiplex 620 you get 3.5 gigs ram and in the Dimension E510 you get 3.2 Gigs ram period End. Doesn't matter if you use 64 bit cpu or OS.
In an Optiplex 745,760,780 you never get the full 8 gigs for the same reason.
That is the reason behind 4 gigs ram (3.5 gigs USEABLE)
You only get the full amount of ram on systems that DO NOT HAVE intel Video or AMD Video or Nvidia Video stealing system ram.
The Precision 380 for example allows the full 8 gigs useable.
Whereas the GX620 is 3.5 gigs useable.
It Gets Worse with E510 / 5150 3.25 Gigs No amount of EMT64 or other bla bla bla Gives you more ram. Adding Video Card DOES NOT RECOVER Stolen shared system Ram.
4 Gigs Max 3.25 USEABLE
speedstep
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May 13th, 2015 05:00
More than 3 Gig requires 64 bit OS and Ram must be installed in pairs. Because the Chipset Steals from the System Ram for Video you will never get 2 or 4 or 8 gigs it will always be 256 meg short aka 1.6 gig or 3.6 gig or 7.6 Gig. Adding a video card does not recover the shared ram.
If you only use the 2 Gig modules what happens? The ejector ears are color coded for the Pairs with White usually being the first pair.
timotheusd
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May 13th, 2015 10:00
Actually, MS' OS's from Vista through 10 Preview show the total installed RAM, (at least in the Control Panel-System window.
Also it has been my experience that installing a video card will always recover the shared buffer for use as system RAM. (Every computer I have worked with would automatically disable the onboard video if you installed an AGP/PCI-E card, unless this behavior has changed so that CPU's with the video subsystem on the CPU can still use that portion of the chip for video compression or something.)
Also, for the record, some 32-bit OS's do support EMT64 which allows the CPU to address more than 4GB of RAM.
The first generation of Intel's Core architecture was a 32-bit core with EMT64, and that is why first generation MacBook Pros cannot be upgraded past Snow Leopard, (as Lion required full 64-bit code execution.
rradicob
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May 16th, 2015 10:00
I took out the two 1GB sticks and now it's shows 4GB installed and 3.25GB usable.
So, I guess that's as good as I'm going to get due to 32bit OS
Thanks for the help everyone