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Dell 7400 RAM upgrade
Hello,
I've recently upgraded my RAM on a DELL 7400 from:
- 8 GB TOTAL RAM (1x 8 GB, 1 slot in use)
- 24 GB TOTAL RAM (1x 8 GB + 1x 16GB, 2 slots in use)
This resulted in a noticeable decrease in performance, when compared with the initial setup (only 8 GB). This is of course not expected.
Removing the 8 GB stick, while keeping the newly introduced one i.e., having:
- 16 GB TOTAL RAM (1x 16GB, 1 slot in use)
resulted on a significant performance improvement, when compared with the initial setup (only 8 GB), which is expected.
So, are there any known issues related to the described RAM upgrade (from 8GB to 24 GB RAM)? Is it a requirement to have both slots with the same RAM capacity?
Grateful for any advice.
Kind Regards.
JOcean
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12.2K Posts
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July 7th, 2022 05:00
With 24GB of RAM, you will operate on dual channel on only 16GB of the total. (the 8GB module and 8GB of the 16GB module). Plus there is a good chance that the modules are not fully compatible based on the make of each module and the module speed and type. The best way to upgrade RAM has always been to install a matched kit of identical RAM modules.
Also you did not specify the speed of the RAM. If they are not the same speed then the RAM will run at the speed of the slowest module.
U2CAMEB4ME
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July 7th, 2022 05:00
Welcome to the Dell Community @ffurtado
First:
The original 8GB and the first 8GB of the 16GB will be "Dual Channel" or as Dell may call it "Dual Interleave"
That means the second 8GB of the added 16GB will run in "Single Channel"
Depending on the applications being ran this can cause a degradation in performance.
Having to constantly switch between Single and Dual channel is where your problem lies.
That's why it is best to have "Matching Pairs"!!!
Best regards,
U2
ffurtado
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July 7th, 2022 05:00
Thanks for replying so quickly as well @JOcean .
Yes, I have not gone into many details: the clock speed and other specs are the same, however they are different manufacturers - which could as well play a role.
So it seems likely that the main cause should be the capacity mismatch between RAM modules.
I'll get a second, identical module, and post again, once I have the chance to test it actually solves the performance issue.
Kind regards,
Filipe
ffurtado
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July 7th, 2022 05:00
Thank you for your kind and quick reply @U2CAMEB4ME !
Best regards,
Filipe
ffurtado
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July 21st, 2022 00:00
Thanks @JOcean @U2CAMEB4ME ,
I've added 16GB to the second slot as well, and can confirm a noticeable performance improvement. Qualitatively, from best to worst:
32 GB (best) > 8 GB > 24 GB (worst)
Thanks again for your help.
Kind regards,
Filipe
JOcean
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July 21st, 2022 04:00
Glad we could help out!