It is DDR3. Here is the owners manual for the 8500.

http://www.dell.com/support/troubleshooting/us/en/19/Product/xps-8500 

???

It's a DDR5 card. Dell only offers GT 640 GDDR5 for x51 and XPS 8500.

The DDR3 is retail. The DDR5 is OEM.

http://www.dell.com/ca/p/xps-8500/fs 

Ok, my bad, Dell seems to be today. Instead of offering GT 640, Dell seems to be stepping down today to GT 620s for all its XPS 8500 models. Anyways, I know for a fact that the card Dell has is the GDDR5 version.

so i got 1 guy telling me its ddr3 one guy telling me its ddr5 great

so i got 1 guy telling me its ddr3 one guy telling me its ddr5 great

I`m not a guy, but I can only tell you what the owners manual for the XPS 8500 shows. Until you can officially open it up and use the service tag number or Belarc advisor, you won`t know for sure.

I hope yours works better than the one I just bought at Costco 3 days ago.

Fails the Windows 8 upgrade advisor.  Dell support says it will run "Awesome", run the upgrade anyway.

Dell coupon for upgrade is no good, pay full price.  4 hour download.

Mouse, Keyboard, Display randomly die and come back to life after Win8 update.

1 hour session w/Dell support installing new BIOS and other software.  Says use it for a day and I'll call back.

Screen still goes black randomly off/on.  Mouse/Keyboard still die.  Goes to sleep mode while typing.

Support now offline, so stuck with waiting till tomorrow I guess.

Thank God for the Costco 90 day, no questions asked policy for computer returns.

One would expect this machine to be Win8 capable out of the box.

Good Luck.  By Christmas, you'll be 30 days into your return cycle.

BTW:  the service tag is on the box.  Large 6" x 6" label.  Labeled Track codes (S/N):

DrexelZ, All,

The sales sites state it is GDDR5. The internal Dell training says it is GDDR3?

Nvidia GeForce GT640 (OHGA3/M209N)
PCI Express 3.0 x16 Full Height
GPU Core Name GK107-400-A2
GPU Frequency 950 MHz
CUDA Cores 384
Graphics Clock (MHz) 797
Memory Clock (MHz) 891
Standard Memory Configuration 1GB DDR3
Memory Interface Width 128 bits
Memory Bandwidth (GB/sec) 28.5
Thermal Solution Active Fan Sink - Fan Controller excluded (2 pin)
Display Support DVI-I/HDMI/DP
HDMI 1.4 support Yes
Nvidia 3DTV Play support  Yes
Nvidia 3D Vision Yes
Nvidia 3D Vision Surround Yes
DP support DP 1.2 

Let me add to the confusion by listing the part numbers...
X51 =
15J9Y Nvidia Geforce 640GT OHGA3 1GB DP/DVI-I/HDMI (Win7)
RCDYV Nvidia Geforce 640GT OHGA3 1GB DP/DVI-I/HDMI (Win8)

XPS 8500 =
YG17P Nvidia GeForce 640GT OHGA3 1GB DP/DVI-I/HDMI (Win7)
CJF72 Nvidia Geforce 640GT OHGA3 1GB DP/DVI-I/HDMI (Win8)

An owner needs to run GPUZ on their video card to tell us what it shows.

I used GPU-Z today, and it shows that it is indeed GDDR5.

Don't know if the XPS 8500 ships with different versions of it??

That would be confusing and infuriating. All I know is that Dell ran out of it or something

because now it's either 7570, 620, 7770, 660 OEM or 7870.

Yours is the only post I have seen on the Costco X8500-4727BK system.  They still have a few left and am considering buying one of these with 12GB RAM and Nvidia OEM GT640 graphics card and upgrading Windows 7 to Windows 8.

Could you please clarify the statement "Dell coupon for upgrade is no good".  Costco offers a coupon to upgrade any Windows 7 to Windows 8 for $14.99.  Is this what you were referring to?  MS regular upgrade price for this is $49 I think.

Did you ever successfully resolve Windows 8 install issues?  As far as the PCIe 1X port issues and problems with USB 3.0 ports, these appear to have been addressed by latest A09 BIOS fixes.  I was also wondering how old are these units being sold in Costco, and if there are any motherboard/hardware fixes delivered in XPS unit shipped from Dell since Black Friday that would not be resolved in one of these older Costco boxed versions.

The alternative is to buy the Costco X8500-3685BK i7, 8GB DDR3, 1GB Nvidia GT620 graphics, loaded w/ Windows 8 and Office Home and Student for same price as other system $800, which still beats Dell's direct order price.

Yours is the only post I have seen on the Costco X8500-4727BK system.  They still have a few left and am considering buying one of these with 12GB RAM and Nvidia OEM GT640 graphics card and upgrading Windows 7 to Windows 8.  After working with wife's new laptop w/Win8, no way that I want to upgrade.   MSFT removed the registry option to downgrade to Win7 in the production version. Could you please clarify the statement "Dell coupon for upgrade is no good".  Costco offers a coupon to upgrade any Windows 7 to Windows 8 for $14.99.  Is this what you were referring to?  MS regular upgrade price for this is $49 I think. I didn't realize that Costco had the $14.99 offer until after I went through the Dell upgrade offer.  I'm still waiting for Dell to reverse the charges to MSFT before I just dispute the AMEX charges.  Walking through the upgrade, enter the Dell code, enter credit card info, Full price charged to card with no warning that the Dell code would not be applied. Did you ever successfully resolve Windows 8 install issues? NO, I returned it to Costco and replaced it with the last one on the shelf.    As far as the PCIe 1X port issues and problems with USB 3.0 ports, these appear to have been addressed by latest A09 BIOS fixes. After BIOS update, still fails the upgrade test.  I was also wondering how old are these units being sold in Costco MFR date is in the June/July timeframe , and if there are any motherboard/hardware fixes delivered in XPS unit shipped from Dell since Black Friday that would not be resolved in one of these older Costco boxed versions.  I have not attempted Win7 to Win8 because I don't want to go through the 3 hour fiasco with Dell support again.  Costco support was 1000% better than the Dell support.  Costco USA based.  Dell offshore based. The alternative is to buy the Costco X8500-3685BK i7, 8GB DDR3, 1GB Nvidia GT620 graphics, loaded w/ Windows 8 and Office Home and Student for same price as other system $800, which still beats Dell's direct order price.  I almost got that one instead but already have 2 full versions and 3 Home/Student copies of Office.