13 Posts
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2190
Using higher RAM frequencies in Dell OptiPlex PC
Hi
I'm looking to upgrade my OptiPlex 7040 with 16GB RAM and I'm currently looking on eBay for second hand RAM as it's cheaper. If I remember reading through the manual the PC is able to take RAM modules rated up 2400MHz.
The problem I have is I can find plenty of eBay sellers selling DDR4 RAM with higher frequencies such as 3000MHz or 4000MHz and these are a lot higher than 2400MHz.
I was wondering if the higher clocked RAM modules would work in the PC at lower frequencies without any compatibility issues (essentially down clocking them)? I'm aware that using higher frequency RAM is overkill but they are selling at 50% cheaper than RRP.
sam55todd
235 Posts
0
September 20th, 2022 09:00
1) RAM modules normally support multiple standards to make them downward-compatible
2) The problem may arise from incompatibility between existing modules and newly installed ones.
As a result it's either won't boot at all (if both {old+new} used) or may work at lower frequencies than before (at whichever fr-cy memory controller could find synchronization between modules).
Optiplexes don't have separate BIOS setting to manage RAM settings.
Thelolman76
21 Posts
0
September 20th, 2022 01:00
If your motherboard supports up to 2400MHz and you get 3000MHz, your motherboard should automatically down-clock your ram speed. On the rare occasion that it doesn't, your PC should be unstable, and you'd know that your motherboard can't down-clock. if that's the case, just resell the ram and attempt to find a cheaper one.
redxps630
7 Technologist
7 Technologist
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10.4K Posts
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September 20th, 2022 04:00
I would be cautious because I have seen Dell optiplex bios reject just a little bit higher than spec speed ram in the past such as 380 rejecting some gaming DDR3 memory. also seen Dell laptop reject DDR4-2666 when spec says 2133/2400. 3000/4000 is way too high. I am surprised you cannot find cheap deal on 2400.
bradthetechnut
6 Professor
6 Professor
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7.4K Posts
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September 20th, 2022 14:00
Speaking of new RAM, I've used A-Tech RAM for years now and it has a lifetime warranty. Not that they're the only good RAM mfr., but if you can buy new, you'll get a better warranty that what's used on eBay. I've gotten A-Tech from Amazon and I think they're on eBay also.
willowen100
13 Posts
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September 28th, 2022 14:00
I ended up getting two 8GB modules rated at 3000MHz and they have downclocked to 2133MHz as shown in the Memory Information section of the BIOS.
sam55todd
235 Posts
1
September 28th, 2022 22:00
On your screenshot it says what RAM is operating in Single-Channel mode which is much slower if compared to Dual-Channel.
It normally switches into Dual Channel if same modules are used and those are inserted in correct slots on motherboard (slots are in pairs).
willowen100
13 Posts
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September 29th, 2022 00:00
It will be most likely the single 4GB module in slot 3.