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Damo123
Bronze

Optiplex 755 USFF cpu and ram upgrade

Hi, The Novice is here 

I have an optiplex 755 USFF which i want to upgrade the cpu from intel pentium dual core e2180 to intel core 2 duo e6850 would the standard heat sink be ok to use still? 

Also looking to change the 2x 1GB Ram to 2x 2GB, do i need to match up the ram to the new cpu? Can anyone advise on what type of ram to get.

Also I've never changed a CPU before is it just a case of taking out old and put in new?

Cheers

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19 Replies
osprey4
Diamond

Re: Optiplex 755 USFF cpu and ram upgrade

Hi Damo123,

That CPU is supported, and the stock heat sink should be fine.

You do not need different memory. Two 2-GB PC2-5300 modules are $72 on Crucial.

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speedstep
Diamond

Re: Optiplex 755 USFF cpu and ram upgrade

Ram Speed depends on CPU FSB.

755's do not support DDR3.

1066mhz fsb cpus require PC2 8500 Ram.

800MhZ fsb cpus require PC2 6400 Ram.

And afaikt thats the max speed of Ram on the 755 chipset.

ark.intel.com/.../Intel-Core2-Duo-Processor-E6850-4M-Cache-3_00-GHz-1333-MHz-FSB

www.crucial.com/.../mpartspecs.aspx

Memory Type: DDR2 PC2-8500, DDR2 PC2-6400, DDR2 PC2-5300, DDR2 (non-ECC)

Maximum Memory: 8GB

Slots: 4 on tower 2 on USFF

Although the memory can be installed one module at a time, the best performance comes from using matched pairs of modules.

How much memory your Windows OS will recognize depends on which version of Windows you are running. 32-bit versions of Windows will see (and utilize) only 3GB or 3.5GB. To utilize more memory, install a 64-bit version of your OS.


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Damo123
Bronze

Re: Optiplex 755 USFF cpu and ram upgrade

Speedstep, i am abit confused im not to sure i understand, are you saying i cant use that cpu because of the ram?

Thanks

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Damo123
Bronze

Re: Optiplex 755 USFF cpu and ram upgrade

Osprey,

thanks for the advise can you see any problems of using that ram with the e6850 cpu? With Speedsteps advise i am now confused lol.

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rdunnill
Diamond

Re: Optiplex 755 USFF cpu and ram upgrade

G.SKILL PC8500 DDR2 2x2gb kit, $65 with free shipping.

I've had nothing but good luck using G.SKILL in my older Dells.

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Damo123
Bronze

Re: Optiplex 755 USFF cpu and ram upgrade

correct me if im wrong as you can tell my knowledge on this is quite bad.

With the e6850 cpu whitch is 1333 fsb, would the ddr2- pc2 8500 be the best match up to it?

Thanks

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speedstep
Diamond

Re: Optiplex 755 USFF cpu and ram upgrade

PC2 8500 is the fastest DDR2 Ram available. Works in ALL 755 models.  With 1333FSB Likely the ram will clock down to 800MHZ aka PC2 6400.  This is just a guess though I am not Dell engineering and I don't have a Cpu to test.

The CPU-Z program would tell you how fast it is or isn't running.  They don't use DDR3 so 1333Mhz ram isn't happening ever.  PC2 5300 RAM does not work with 800MHZ FSB or higher CPUS.

Friendly Name Industry Name Peak Transfer Rate FSB
DDR2-400 PC2-3200 3200 MB/s 400
DDR2-533 PC2-4200 4266 MB/s 533
DDR2-667 PC2-5300 5333 MB/s 667
DDR2-800 PC2-6400 6400 MB/s 800
DDR2-1066 PC2-8500 8533 MB/s 1066
Clock Speed 2.66 GHz
L2 Cache 2MB
FSB Speed 533 MHz
Clock Speed 3.0GHz
L2 Cache 2MB
FSB Speed 800 MHz
Clock Speed 2.66 GHz
L2 Cache 4 MB
FSB Speed 1066 MHz


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Damo123
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Re: Optiplex 755 USFF cpu and ram upgrade

Speedstep,

if the pc2-8500 ram would clock down to 800MHZ i know this was a guess, but if it does clock down i might aswell go for pc2-6400 which is already 800MHZ??

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speedstep
Diamond

Re: Optiplex 755 USFF cpu and ram upgrade

YMMV.  I know that PC2 8500 works with all models all cpus aka it can work at the slower speeds.   I cannot answer that question because I do not have a 1333mhz cpu and do not know what the chipset does with the ram.  I do know that DDR 2 has a max speed of PC2 8500.  Only the designer of the board or perhaps Intel would be able to tell you. My Guess is that 800MHz memory although faster than 667MHz memory will only run at 666.5MHz speed on a 1333MHz FSB. If you guess wrong the ram will not run.

Friendly Name Industry Name Peak Transfer Rate FSB
DDR2-400 PC2-3200 3200 MB/s 400
DDR2-533 PC2-4200 4266 MB/s 533
DDR2-667 PC2-5300 5333 MB/s 667
DDR2-800 PC2-6400 6400 MB/s 800
DDR2-1066 PC2-8500 8533 MB/s 1066



Report Unresolved Customer Service Issues here
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The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support




 


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