Mixing Memory on Two Channel Four Slot Setup

[JaredDM]

Oddly this is my first time ever asking a question on here, haha. Usually I only answer them.

I have a GIGABYTE G1 Gaming GA-Z97X-Gaming 3 motherboard which had four memory slots and runs in dual channel memory mode. It is currently running 2 x 4Gb and I need to upgrade it. Since the price to buy a 16Gb kit is only $15 more than buying another of the same memory kit that's already in there I'm thinking of going with that.

I'm just wondering if there would be any speed impact of leaving my old memory in there and having two different size kits mixed in there (they are all the same speed specs DDR3-1600). I would assume that the two gray slots are one set in dual channel and the two black slots are a different set in dual channel mode. So having two separate kits of different sizes shouldn't hurt right? As long as they are paired together properly?

Or am I missing something? Normally I never mix.

 

[JackNaylorPE]

If they are the same brand, same speed, same timing (and hpefully same OM modules), you shouldn't have much of a problem, may have to raise DRAM voltage a pinch. It may impact your CPU OC as CPU has moire modules to control. You can also sell the other ones.

Curious .... what are you using that is finding 2 x 4GB inadequate

 

[JaredDM]

Actually this system isn't OC'd at all, nor has it ever played a single game (though it would be good for it I suppose). So I don't think any voltage adjustment will be necessary. The system is used solely for data recovery work using PC-3000. I just use up a lot of RAM dealing with the huge amounts of data that go through and are analyzed using this system. Today it maxed out the 8GB so badly I finally had to press the reset button because it couldn't even load task manager. Typically it's running around 70% when it's not even being heavily used.

24Gb might be overkill, but since I already have the RAM might as well use it. If it presents any problems I can always use it to upgrade another system here. But, this is the one that really counts because I sit in front of it all day.

 

[JackNaylorPE]

The DRAM voltage adjustment is unrelated to gaming or OCs. It comes from your CPUs IMC having to coordinate 4 modules instead of 2 and 2 different sets of modules which have not been tested together and therefore likely to require more voltage for stability.

 

[Tradesman1]

Give it a try and see, if any problems, let us know and we can try voltage/timing adjustments to try and stabilize.If you just go 16GB, regardless will still have 16GB and if the old will play it will be a bonus

 

[JaredDM]

Exactly. I'm sure 16GB will be enough for now, I'm really just planning ahead for future possibilities. Stability is key in this application, so even one BSOD is one too many.

 

[Tradesman1]

Agreed, but getting a BSOD from mixed memory can be expected and it often does take voltage/timing adjustment - that's why it's always best to get the full amount you want/need in a single package - they have been tested to play nice

 

[JackNaylorPE]

We've been having this discussion in another thread for a gaming box and the viability of 2x4Gb going forward. The most oft used reference for this discussion is a November 2010 article where it shows no improvement in fps over 8 GB. While I think that was a good argument and served well from 2010 all the way thru 201.

From 2014 - 2016 we saw a transition period where many enthusiasts moving from 2 x 4 GB to 2 x 8GB as their "go to" builds. In 2016, I think that transition is over. Back in 2010, 1 GB GFX cards was the norm and today 4 GB of VRAM is deemed moist suited for 1080 p / 1440p. And while I wouldn't suggest the same four-fold increase in RAM amount, we are seeing fps affected significantly by having just 8GB in games like Witcher 3 and GTAV, more so in SLI / CF. The system you build today will, I expect, be expected to be around and 2020 and I don;t expect 8GB to fare well till then.

But in your case, with the cost of the 2 x 8GB GB being close to the 2 x 4 GB, and not knowing the demands of your subject application, i would be looking at 3 alternatives:

1. Sell the 2 x 4 GB set and spend just $15 (OK, say $25 for selling used) to get the 2 x 8GB
2. Sell the 2 x 4 GB set and get 4 x 8GB matched set, since budget for the 1st 2 x 8GB didn't seem to be an an issue and those extra 2 sticks could very well be paid for by selling the 2 x 4Gb set.
3. Use the 2x 4Gb + 2 x 8GB ... Ya may wanna invest some time in some benching your program tho.... if it won't use more than the 16Gb, it could actually run slower w/ 24GB

 

[JaredDM]

As I had mentioned before, this isn't a gaming rig, it's used solely for data recovery. So while I use mass amounts of RAM, performance is generally a moot point. However stability is a high priority, I'm actually only upgrading because I finally crashed the system from maxing out the 8Gb while running 5 concurrent data recovery processes. Most of the RAM is actually being utilized by the logging of the applications during the work, so it's a slow gradual fill up.

I tried the two sets together just to see, and it wouldn't even post to BIOS (UEFI technically I suppose). So I guess that answers my question about stability. I'll stick to 16GB for now and throw the 8GB kit in another system that could use an upgrade. I actually just now realized that I have the same kit in another computer here which I think was bought the same time. So I can make that into a 4 x 4GB set too.

 

[Tradesman1]

As I had mentioned before, this isn't a gaming rig, it's used solely for data recovery. So while I use mass amounts of RAM, performance is generally a moot point. However stability is a high priority, I'm actually only upgrading because I finally crashed the system from maxing out the 8Gb while running 5 concurrent data recovery processes. Most of the RAM is actually being utilized by the logging of the applications during the work, so it's a slow gradual fill up.

I tried the two sets together just to see, and it wouldn't even post to BIOS (UEFI technically I suppose). So I guess that answers my question about stability. I'll stick to 16GB for now and throw the 8GB kit in another system that could use an upgrade. I actually just now realized that I have the same kit in another computer here which I think was bought the same time. So I can make that into a 4 x 4GB set too.

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+1 For your purposes, stability is key and even if it was a gaming rig, the problems will upset people, we get multiple new threads daily of people mixing DRAM, even the same exact model

Note: if you have problems setting up the 4x4GB give a shout