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1659191
16GB Ram (4x4gb) Supported? Optiplex 755 and XPS 420
I have multiples of the Optiplex 755 and XPS 420's-
They're great little machines for virtualization.
I currently have them all "maxed" out at 8GB RAM apiece, which is the listed maximum for each.
Often I've found those "maximum" specs to be based on the largest dimm available at the time of publish, and not necessarily a system limitation.
Do either of these machines support 4GB Dimms?
OCZ and Geil both have PC800 4x4GB Kits available, and it would be well worth it for me to upgrade if possible.
Thanks and Best,
Shane
camachofc
5 Posts
1
September 28th, 2011 08:00
GzBz
1 Message
1
February 2nd, 2012 14:00
Tested and known working!
Dell Optiplex 755 with BIOS A20 running 16GB RAM
G.Skill PC2 6400 4 x 4GB - CAS 5-5-5-15
alainsaintpierr
1 Message
0
December 2nd, 2012 03:00
Hi,
Question about your Optiplex 755 (BIOS A20), is it built around an Intel Q35 Express chipset? If yes you are sure it does recognize all 16GB of RAM?
Regards,
timotheusd
30 Posts
2
May 27th, 2015 09:00
There are a multitude of things that play into the maximum memory capacity of a machine, aside from the obvious how many RAM slots.
32 vs. 64 bit OS environment:
while there are some exceptions, a 32 bit OS is limited to 4GB of total address space, (this includes all hardware I/O addresses and dedicated video RAM where applicable)
Chipset support:
This is probably where the rubber meets the road for your issue. I'm not completely clear on the details, but it boils down to what is referred to as "Organization" essentially, "How many RAM chips can the chipset deal with?" We're not talking about "Sticks" or "Modules" here, but the number of actual chips that are mounted on the DIMM.
From previous posted comments, it appears to be confirmed that these machines will accept 4x 4GB sticks, and this is most likely a result of RAM manufacturers using newer (smaller) processes to place more transistors on a single chip. Dell does not officially support this because because they were not able to test it when they were designing the machine.
It appears that Intel built the chipset and reference design to support 16GB total, and Dell didn't stray from the reference, but also never had a reason to go back and thoroughly test 4GB sticks, so they officially remain "unsupported" even though the chipset will fully utilize them.
sverstegen
6 Posts
0
September 25th, 2009 15:00
I see now that the 8GB limit is likely a fixed limitation of the intel chipset on these boards. Opti 755 uses Q35, XPS 420 uses X38.
If anyone has had different experience here, I'd love to hear about it- please do post your results.
Thank and Best,
Shane
camachofc
5 Posts
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March 7th, 2011 21:00
I have an optiplex 755 which had 4gb (2x2gb sticks) I just added a single Patriot 4gb stick and it recognized it fine. I now have it running at 8gb. Now that I know it can read a single 4gb stick I wonder if it would take 4 of them to max it out at 16gb.
camachofc
5 Posts
1
June 30th, 2011 15:00
I have 12GB on my 755 DT (2x4GB) (2x2GB)
lixenft
6 Posts
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September 27th, 2011 04:00
I have two Optiplex 755 SFF running VMware ESX 4.1 with 8GB. I want to extend the memory to maximum
Can anybody clearify this Statement from the product brief:
"Delivers up to 12.8 Gb/s (DDR2 800 dual 6.4 Gb/s) of bandwidth and 8 Gb memory addressability for faster system
responsiveness and support of 64-bit computing"
Does this mean 6.4 Gb/s and 8GB accessability per channel, or is the adressability limited to 8GB over both channels?
Thanks
Thomas
speedstep
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September 27th, 2011 05:00
8 Gig is total Maximum Memory with 2 Gig Dimms.
4 Gig DDR2 Dimms do exist but I'm not aware of Crucial or other vendors supporting more than 8 gig total.
DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64 • Part #: CT722584
Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor)
lixenft
6 Posts
0
September 28th, 2011 03:00
Can you give me the type of the working 4GB modules?
Thanks
Thomas
lixenft
6 Posts
0
September 28th, 2011 05:00
"Can you give me the type of the working 4GB modules?"
No.
I've never seen 4 gig DDR2 un buffered low density Dimms.
Can this match?
www.amazon.de/.../ref=sr_1_6
speedstep
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September 28th, 2011 05:00
"Can you give me the type of the working 4GB modules?"
No.
I've never seen 4 gig DDR2 un buffered low density Dimms.
speedstep
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September 28th, 2011 09:00
Interesting.
Newegg.com - Patriot Signature 4GB 240-Pin DDR2 SDRAM DDR2 ...
Patriot PSD24G8002 Signature DDR2 4GB (CL6 PC-6400, 800MHz ...
camachofc
5 Posts
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September 28th, 2011 17:00
That's the one on newegg.
musicman2
3 Posts
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October 7th, 2011 05:00
Hey do you think this will work on the Dell OptiPlex 745 with the ultra small form factor? it only has 2 slots and just like the small form factor with 4 slots it says that the max capability is 2 gb per slot. Of course you guys have proven that wrong. Do you think a 4 gb stick will work in the ultra small form factor as well?