My Dell SC420

Memory Upgrade

I checked on Intel's website and for the E7221 chipset, it's clearly stated that 4gb is the maximum supported and 2gb or 4gb dimms are specifically not supported. It seems a bit of a shame since the same Intel docs also states that 'the Intel® E7221 chipset is specifically designed to support Intel® Extended Memory 64 Technology' (both taken from 'Intel E7221 Chipset Memory Configuration Guide')

Interestingly, I also found the doc 'Intel E7221 Chipset datasheet' where it's stated that

'By using 1Gb technology, the largest memory capacity is 8 GB... Though it is possible to put 8 GB in system by stuffing both channels this way, the MCH is still limited to 4 GB of addressable space due to the number of address pins on the FSB.'

I guess this could explain how some people have reported using 1 4gb dimm and an SC420 seeing all 4 gigs - but presumably then adding another 4gb dimm wouldn't work. 

CPU Upgrade

The FAQ states that 'any current' LGA-775 CPU would be OK but I have found other posts stating that dual-core LGA-775 processors are not compatible. I know then that whatever I get, it's got to be LGA-775 but not every LGA-775 will work. Does anyone know, definitively, what the fastest processor I can use is? My actual aim is to find a CPU with EM64T and VT support, and while I'm upgrading I may as well get the fastest available. However, while I can find definite success stories regarding EM64T, I can't find any SC420 hits regarding VT. I have seen a post claiming success with a P4 Extreme Edition, which is the fastest CPU I think so far confirmed, but Intel's processor info site tells me none of the P4 EE chips support VT.

Video Card Upgrade

Software Upgrade to SC420's E7221 chipset

"As it seems that SC420's E7221 (CopperRiver) chipset is internally almost identical with Intel 915G/GV/GL chipsets, I suspected E7221 too has 3D acceleration engine in it just as 915 does."

"So far I have only succeeded to make (seemingly) 3D acceleration engine's configuration registers visible to the system. I can't move forward from there though because I don't know what would be the right register setting." 

"The util is designed to enable (together with Intel's 915 driver) the DirectX9 capability of the integrated graphics, so most DirectX9 games will work. However, some applications which explicitly check existance of particular Direct3D function may fail to run."

"One big caveat: this enabler is not quite compatible with ECC memory. Using overlay or 3D acceleration with this enabler on ECC memory configuration may result frequent reboot/freeze."

Here's the procedure to install GMA900 video driver and apply E7221 patch V0.05 on my SC420 system. NOTE: This patch is very immature. Tested casually on XP SP2 only.

    1. Download GMA900 video driver from Intel web site. It is available for download at
      1. : For Windows XP Home Edition
      2. : For Windows XP Professional Edition
    2. Unzip the file.
    3. Follow the MANUAL "HAVE-DISK" INSTALLATION INSTRUCTIONS documented (except the final reboot step) in the ReadMe.txt file. "Intel(R) 82915G/GV/910GL Express Chipset Family" is the display adapter you want to choose.
    4. At the final step of the installation, click on the "No" button to not reboot and finish installation without rebooting.
    5. Download the patch from one of the following workable link. Unzip it and GMApatch001.exe will be there. Run it. 
      1. You will see a full of ????s  Click on the "Yes" button, then on the "???(C)" button to close the window.
    6. Reboot your system.
    7. Now the patched driver should be working. Enjoy!
This time the 915 driver doesn't need to be modded. Install the enabler by right-click SoftGMA.inf and choose Install. After reboot, the OS will detect a new video controller and will ask you to install driver for it. Then install the stock 915 driver.

Open Device Manager, choose View->Show hidden devices, and look for SoftGMA Enabler under Non-Plug and Play Drivers. If one doesn't exist, reinstall the patch.

If one exists, open its properties page, open Driver tab, and look at its status. It should read Started. If not, reinstall the patch...

BTW stock SVGA driver built in Windows XP is smart enough to set the resolution of 1280 x 1024.

The latest 915 driver as of now is this:

Here's the uninstallation procedure, if it doesn't work.

1. Launch registry editor (regedit.exe).
2. Open "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\GMAEnabler" key.
3. Delete "GMAEnabler" key.
4. Delete GMAEnabler.sys in the drivers folder. If your Windows installation is in the C:\Windows folder, the drivers folder is C:\Windows\system32\drivers.
5. Reboot your system.

  1. An very interesting and fun-to-read article, SC420 and Cedar Mill, discussed about if a 65nm Cedar Mill Pentium 4 can be used on Dell SC420.  My answer is YES.  
  2. For a decision on which Pentium 4 is best for your SC420, a List of Intel Pentium 4 Microprocessor should be very handy.
  3. Official explanation of the software approach is the post by xcrOSgS2wY  Trying to enable 3D acceleration of SC420 integrated video.
  4. A detailed explanation of how to modify Dell SC420 PCIe x8 slot to be PCIe x16 compatible can be found on Dell Poweredge SC420 PCI Express 16x Video Card MOD
  5. A list of workable video card for Dell SC420 can be found on UPDATED 4/12/05: Lowest Risk Video Card for the SC420....Is and Using a x16 video card in a SC420