Dell Optiplex 780 USFF CPU

Question

Hi all,

I have a Dell Optiplex 780 USFF pc with an Intel Pentium E6700 3.20GHz CPU, I was wondering what other CPU’s this PC supports?

I am looking to replace the CPU and RAM as the PC seems to lock-up even after it’s completed it’s POST. So for example when I press F2, it will hang on the Intel Matrix Storage Manager screen and not go into BIOS and the keyboard buttons do not respond when pushed.

I have performed a system diagnostic test and all basic tests come back as fine.

Many thanks!

GarethS10 · Answer

I appreciate what your saying, however I got gifted the PC and would like to get it working properly if possible hence my question. I have already replaced the CMOS battery.

Mary G · Answer

It would not help upgrading the cpu on this 13 yr old small Vista computer even if you could. Save your money to replace it. The service manual doesn't even mention replacing the cpu.

Dell OptiPlex 780 Service Manual--Ultra Small Form Factor Computer

What you could replace is the coin cell battery for about $1 at any store that sells batteries. See the manual. A bad coin cell prevents booting.

bradthetechnut · Answer

Optiplex 780 Tech Guide.pdf

First (just in case), no waiting for the Dell logo or a keyboard light to enter BIOS. Repeatedly push F2 at startup.

In the tech guide, CPU upgrade options are on pg. 8. Top listed CPU for the 780 USFF is the Intel® Core™ 2 Duo E8600/3.33GHz.

For RAM options, search the guide using "memory."

GarethS10 · Answer

Many thanks for that. In that guide, it shows the RAM being upgradeable to 8GB on the USFF 780, have I understood that to be correct? I thought it was only upgradeable to 4GB max?

bradthetechnut · Answer

Indeed, 8GB RAM is the max.  May be you got the '4GB' idea from a different Optiplex?  Just as an example, the 755 had 8GB max for MT, DT, & SFF; 4GB for USFF.  8GB is much more ideal for Win10 than 4GB.

redxps630 · Answer

correct that USFF can support 2x4 gb = 8 gb ddr3 desktop memory.

https://www.dell.com/support/kbdoc/en-yu/000132093/optiplex-780-ultra-small-form-factor-usff-removal-guide-for-the-memory-system-fan-heatsink-intrusion-switch-and-power-supply

speedstep · Answer

@GarethS10  Most modern games want 8 gigs minimum and quad core cpu. So update bios Then add ram Then install win10 oem dvd. Update cpu to quad core https://www.youtube.com/watch?v=J8ja79SlA-g CT2K51264BD160BConfiguration ID: CT7339271DDR3-1600 • CL=11 • NON-ECC • UDIMM • 240-pin • 1.35V • 2Rx8 • PC3-12800 Intel® Core™ 2 Quad Q9650 Intel® Core™ 2 Quad Q9550 Doubles performance. Dual vs Quad core

bradthetechnut · Answer

Hi @speedstep,

According to the Tech Guide, the USFF does not support quads. Isn't that also a power and heat issue since the quads are 95w and the duos 65w? I thought that was the stance you used to take.

speedstep · Answer

@bradthetechnut  You are correct Intel® Core™2 Duo Processor E8600 , 3.33 GHz, 1333 MHz FSB is 65W. USFF power is too low to support 95W cpu. DT is cheap however. https://www.ebay.com/itm/155031965196 Tower is always recommended due to ability to support larger video cards. So a DT shell without hard drive could migrate parts from the SFF without needing reinstall. Tower is always a better investment. https://www.ebay.com/itm/175362805070 If planning on upgrade further then should not be over $100 because 790 and 7010 and 7020 are a better deal.

user_4ab17e · Answer

Well, I do have an Optiplex 780 USFF too, and I am satisfied with my Core 2 Duo e8400. It used to be very high end in its time. It will be a solid choice, On the ram side I am having 6GB of DDR3 memory maybe a little bit less for today's standard but okay for web browsing, It can even run some AAA titles like- San Andreas at 1400x900, Modern Combat 5, GTA Vice City.... And I'm also having that BIOS related problem.....

Optiplex Desktops

Dell Optiplex 780 USFF CPU

Intel® Core™2 Duo Processor E8600 , 3.33 GHz, 1333 MHz FSB is 65W. USFF power is too low to support 95W cpu.

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