Mix & Match RAM slots

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Hi all-

Been running 4 GB RAM on this thing for too long, so I ordered an 8 GB chunk. Hard RAM was getting maxed out at 80% occasionally, and with a 5400 RPM HDD, the swap file is slower than Molasses in January; the program I’m using usually crashes when it has to start using it.

Question: In Ye Olde Days (10+ years ago), the amount of RAM in each slot had to be equal as to capacity, and in some cases, brand. In these modern times, can one slot have 4GB OEM and one 8GB of another make for a total of 12? This is my only PC, and I don’t want to fry it!

I’d be happy with 8, but “The mo’ RAM, the better!”

Reason I’m doing it this way, I’m on a tight budget (Senior on SS, $600 car repairs last month, $$$ to dentist this month!), and could only afford one chunk of 8GB this month.

(Next month, if the dentist leaves me anything, I’ll get another 8 GB chunk for the 16GB max!)*

—

(“Dentist, n: a prestidigitator who, by putting metal in your mouth, pulls money out of your wallet.” -Ambrose Bierce)

 

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"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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Having matched pair(s) of RAM allows dual channel capabilities, if your computer is designed for it.

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Nibbled To Death By Ducks

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dual channel only happens with both the capacity AND speed of two RAM chips match

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NetDef, Nibbled To Death By Ducks

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Yep, matched pairs, as stated above.

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Nibbled To Death By Ducks

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EP said …
dual channel only happens with both the capacity AND speed of two RAM chips match

I don’t think that’s exactly the case …

While dual channel (triple channel & quad channel) requires the memory to be of the same capacity and architecture, different memory speeds can be intermixed within the same channel(s) & it will still run in dual, triple or quad channel mode but at the speed of the slowest memory installed within the system.

Example: 3 memory sticks of the same capacity & architecture but with 3 different speeds installed in a system supporting 2 dual channels will result in one dual channel running in dual channel mode but at speed of the slowest memory installed regardless of whether or not the slowest memory is installed within the dual channel pair slots while the 2nd dual channel pair slot with the single memory stick will run in single channel mode and again at the same slowest speed of all 3 memory sticks installed.

Also, when mixing different memory capacities within channel(s), flex mode results which is essentially, a hybrid of dual, triple or quad mode where up to the highest memory address of the lowest capacity memory within the channel, the channel runs in dual, triple or quad mode and subsequent higher memory addresses run in single channel mode.

A good description of this from Intel can be found here.

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NetDef, Nibbled To Death By Ducks

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[EP]

another problem OP may have is that running different RAM chips with different speeds may cause all RAM chips to run at slower speeds or may lead to some instabilities.

while having two different RAM chips with different capacities may work, be sure that the installed RAM chips have the SAME SPEED

• This reply was modified 3 years, 6 months ago by EP.

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Nibbled To Death By Ducks

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[NetDef]

For optimal performance and (perhaps more importantly) stability, the capacity, speed, CAS latency and CL timings should all match. You should also refer to your motherboards documentation to make sure you use the correct pairs of slots for dual/triple/quad mode to function properly.

Many performance enthusiasts also like to get matched manufacturing batch pairs, although I am not convinced that actually makes a difference.

See https://www.crucial.com/articles/about-memory/difference-between-speed-and-latency for a decent explanation of the metrics involved.

On a side note: If you are even thinking about overclocking, then use precisely matched pairs only!

~ Group "Weekend" ~

• This reply was modified 3 years, 5 months ago by NetDef.

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Having ‘improved’ a number of computers by adding memory, I rely on NewEgg’s memory finder, which is built into their site. “It provides vendor-neutral specifications and product suggestions to locate find memory that fits a specific system.” In reality, it is just part of their regular search function… just enter your hardware and ask for RAM. They have a How to page.

Non-techy Win 10 Pro and Linux Mint experimenter

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RDRguy, Nibbled To Death By Ducks, Lars220

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Wow! What response & speed! Everyone must be home due to the emergency.

OK…both are DDR-3 1600 MHz units. So I am a go for 12GB, but with ” less overall efficiency” Single- channel on some of the RAM than if they were both the same ? No frying?

(The E6330 must have been made in a RAM-expensive time; 2014)

Thanks for your patience, I’m still a bit woozy from yesterday.

Win7 Pro SP1 64-bit, Dell Latitude E6330, Intel CORE i5 "Ivy Bridge", 12GB RAM, Group "0Patch", Multiple Air-Gapped backup drives in different locations. Linux Mint Greenhorn
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"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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RDRguy

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As long as both your system board & RAM is fully functional to begin with & you don’t damage the board’s memory slot pins or memory pins installing the memory & most importantly, you don’t zap either the board or memory via a static discharge when you’re handling them, I predict everything will work just fine.

In Flex mode, your system will be quicker than just using single channel mode but slower than if all your memory was running in dual channel mode.

Be sure to ground yourself before handling the board or memory – simply touching one of the screws securing the wall switch plate (or socket plate) should work but do it after you’re already sitting at the work table & ready to install the memory so you don’t end up building up another static charge walking on the carpet in your wool sweater while holding your PBJ in/on a plastic baggie/plate & milk in a plastic cup 🙂

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Nibbled To Death By Ducks

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Thanks!

Oh, and BTW, an associate of mine said years ago, “Oh, don’t worry so much about the RAM slabs; they’re buffered well enough.”

True?

(I’m still wearing my wrist strap to ground…BTW, I built my last three PC’s, so I’ll be careful.)

I specified the components on the 4th, a workstation that’s in storage,  and had a custom shop do it….got a 1 year guarantee that way…and I only had to take it back twice to have it done right! Used to be in QC/QA for a time on Mil-Spec. Found out “No one loves a cop.”  🙂

Win7 Pro SP1 64-bit, Dell Latitude E6330, Intel CORE i5 "Ivy Bridge", 12GB RAM, Group "0Patch", Multiple Air-Gapped backup drives in different locations. Linux Mint Greenhorn
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"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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RDRguy

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Wrist strap? QC/QA? Mil-Spec?

These are very familiar terms I had to deal with everyday before I retired.

Hey you’re not the guy I always interfaced with back in the engineering lab when I was still working are you 🤔

And yes, modern technology these days does provide much more robustness in component design & manufacture so modern memory these days isn’t “as delicate” as it once was in years past.

I guess I’m still old school & practice what I was taught (& experienced) in my earlier years – a few circuit boards that worked & then didn’t all because I was in a hurry and didn’t attach my wrist strap to the grounding point.

My motto is: It’s always better & usually less expensive to be safe than sorry.

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Groups A, B & ABS

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Nibbled To Death By Ducks

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Eh, we had a service disconnect and I ran out of edit time 🙁

Wanted to ask you, RDRguy, if it mattered which slot the 8GB went into, and which slot the 4GB should go into, i.e. slots 1& 2..

…or that, no matter what config that is, the system is smart enough to figure it out?

…and I’m definitely going to see an improvement in performance with 12GB vs. 4GB, and an even greater when next month rolls around and my wallet is loaded again…if anyone on SS can use the word “loaded”… :p

Win7 Pro SP1 64-bit, Dell Latitude E6330, Intel CORE i5 "Ivy Bridge", 12GB RAM, Group "0Patch", Multiple Air-Gapped backup drives in different locations. Linux Mint Greenhorn
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"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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Unless there’s a specific note concerning this different memory capacity setup in your system manufacturers manual or spec sheet, I can only suspect that the system should be able to figure it out as long as they’re both in the same dual channel pair slots.

Win7 - PRO & Ultimate, x64 & x86
Win8.1 - PRO, x64 & x86
Groups A, B & ABS

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Nibbled To Death By Ducks

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RDRguy wrote:

Wrist strap? QC/QA? Mil-Spec? These are very familiar terms I had to deal with everyday before I retired. Hey you’re not the guy I always interfaced with back in the engineering lab when I was still working are you 🤔

I doubt it, unless you’re named “John”, went on to work for DCAS, and had a boss we all called “Froggy”. 🙂 Weird boss, too, a slave driver who would stand there tapping his foot by the punch clock watching us all clock in…and then would turn right around and publicly send a sick man home when it was obvious they were suffering. Hired me on the spot; said, “I don’t believe in keeping HR busy with endless interviews once I found somebody. Report next Monday.” Inscrutable old cuss. I’ve worked for worse.

Much worse.

Win7 Pro SP1 64-bit, Dell Latitude E6330, Intel CORE i5 "Ivy Bridge", 12GB RAM, Group "0Patch", Multiple Air-Gapped backup drives in different locations. Linux Mint Greenhorn
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"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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RDRguy wrote:

Unless there’s a specific note concerning this different memory capacity setup in your system manufacturers manual or spec sheet, I can only suspect that the system should be able to figure it out as long as they’re both in the same dual channel pair slots.

Well, I performed the operation, did a F12 boot into diagnostics, (“Alert! The system memory amount has changed!”) (I sure hope to **** it did!), and ran a “quick” (1/2 hr) Mem check/RAM test…and man, is this thing fast now!

Everything seems to boot at least 200% faster, and at idle, it used to take 35% of the hard RAM just for that…now it’s 14%! Whoopee!

(Only glitch was the *&^%$** RAM holder clips-cheap as anything I’ve ever seen on a MOBO: they deformed under the lightest pressure, and I had to gently coax themselves back into shape. Dell, you should know better! (030XCG [SOCKET 0])

I may be content with what I have now-12GB-as I don’t want to fool with those cheap, lousy RAM clips ever again!

Thanks, all of you, for the help, especially RDRguy!

Win7 Pro SP1 64-bit, Dell Latitude E6330, Intel CORE i5 "Ivy Bridge", 12GB RAM, Group "0Patch", Multiple Air-Gapped backup drives in different locations. Linux Mint Greenhorn
--
"Nine out of 10 doctors say Acid Reflux is mainly caused by computers."

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Elly

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Nibbled: Just curious,  what memory did you use in your upgrade?

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I do lots and lots of memory upgrades for clients.  I have a good stock of DDR3 RAM on hand and some DDR4, and I do several things to assure that the memory will work:

1. Make absolutely sure that the memory meets the minimum specs required by the computer.
2. Match the specs of all the memory used.  On a 4-DIMM system, match the specs of individual pairs, at minimum.
3. Run MEMTEST-86+ for at least one test cycle.

Works for me 100% of the time.

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