Dell Optiplex GX520 Memory Upgrade

I looked at putting a second hand card in the machine (Geforce 8400 or 9400) but before I did that I had a look at the BIOS. Under Video -> Video Memory Size, I have 8 MB selected, however I am missing 500 MB of my RAM in windows 7 (64-bit). Is there any reason for this, what is using the memory? It seems fairly ridiculous to use up 500 MB for a framebuffer for an 8 MB video card.

Hi rlwolfcastle,

The 8MB video memory showing in the BIOS is the internal memory for the integrated video card also it will share 500 MB from the RAM on the system.

Does the motherboard chipset support physical address extension? If not then even though the processor and the operating system support 64 bit and PEX the maximum useable memory will be limted to approx. 3.5Mb. I have a laptop which is the same, it has a 64 bit processor, a 64 bit Win 7 but the mobo chipset only uses 3.5Mb of the 4b I have iinstalled. There is no work around other than changing the mobo.

You can install 2 x 2 Gig Dimms PC2 6400 and it will show 4 gigs in BIOS but 3.5 gigs is max regardless of 64 bit CPU and OS.  This is a Chipset Limitation with this model.

Recommended Upgrade

I'm having the same issue. Installed 4gb (2x2gb DDR2-800/667/533) PC2 6400, 5300 4200 compatatible on a GX520 with Win7 64 bit version. Installed memory shows 4gb but only 3.49 usable. I have not updated the bios. Is this a limitation of the motherboard itself? should i bother updating the bios?

Thanks

Its a limitation of the chipset. GX620 or 520 is the same 3.5 gigs max.

HI: Here is my two cents worth

I put this RAM in the computer

Source: SPD
    Memory Size: 2.00 GB
    Memory Type: DDR2-SDRAM (PC2-6400 / 800 MHz)
    Memory Manufacturer: Kingston

 two sticks - thus 4 GB. the BIOS says there is 4 and Win7 home premium says 3.5 avaliable. So the chipset does limit what can be used.  sigh.

The computer is the GX 520 SFF,

Name: Intel(R) Pentium(R) 4 CPU 3.00GHz
  Cores: 1
  Threads: 2
  Signature: F43h
  Technology: 90 nm
  Performance
    Max Qualified Speed: 3.00 GHz
    Current Speed: 2.99 GHz
    Multiplier: x 15.0 (14 - 15)
    FSB Speed: 798.03 MHz
    Bus Speed: 199.51 MHz
  Features: MMX, PSE36, EM64T, SSE, SSE2, SSE3, XD
  Cache Summary
    L1 Trace Cache: 12 Kuops
    L1 Data Cache: 16.00 kB
    L2 Cache: 2.00 MB

The only issue I've had, is that I occasionaly get the lights 3 and 4 on, showing a memory malfunction. I open the case, wiggle the memory and then it boots up fine. i fear the memory slot is going wonky.  I've swapped memory sticks around, but get the same issue.

I really don't want to do a motherboard swap, so will just have to keep an eye on it.

all the best y'all

Hello,

I recently tried to upgrade from 1GB to 4GB and Windows 7 Home Premium would not complete the startup process. It wouldn't get past the Windows Loading screen. I tried to install 4GB (2x2GB) mushkin PC2-5300.  I removed 1GB (2x512MB) Kingston PC2-4200U.  I purchased the new RAM from New Egg and used their Memory Finder tool. I went with the cheapest 4GB memory combination. I purchased the same exact kit for my GX620 and it booted fine.  After some troubleshooting I decided to try to have just one new stick installed and it booted fine.  Does this mean my system can't handle 4GB? If not, would it be beneficial to put one of the 512MB sticks back in, even though they wouldn't be a matching pair?

I am having a similar problem with the exception that when I get to the Windows start screen it will load ONLY if I let it set and wait for almost 30 minutes for it to continue. I have Windows 7 Pro with 4 gigs, 2x2 OCZ  duel sticks of PC2 6400 of memory.  Once loaded it runs pretty good with the exception of the on board video not being able to be updated. I didn't want to buy a video card if I didn't have to.