RAM: 4x4 OR 2x8 ?

[Zoom123]

Hello,

Price aside, what is better to get 16GB of RAM: 4 sticks of 4GB each, or 2 sticks of 8GB each?

This will be for a z68 motherboard with 4 RAM slots with an i7 2600K which will be overclocked.

 

[Herald85]

2x8GB usually provides better stability (less stress on memory controller) and provides a feature upgrade path. If price is of no concern definately get 2x8.

 

[Kristijonas]

Herald85 answered well for Z68. Just make sure you insert your RAM into the same color slots.
What about IVB and Trinity? Will they support quad-channel memory? In that case, will 4x2gb make sense?

 

[ncalipari]

Future upgradeability or reliability and performance?

I disagree with herald when he says that 2 modules have better stability. The additional load on the memoty controller is negligible given the today technology, anyhow with 4 modules you have:

1) Higher reliability, as the failure of a module will only compromise 25% of your memory and not 50%

2) Lower cost: 4 gb modules are much cheaper

3) Higher performance: it's less likely that a module can be busy. Don't expect huge improvements.

 

[Kristijonas]

But ncalipari, Z68 doesn't support quad-channel memory, so there should be no improvements in performance whatsoever? I'm very interested if Ivy Bridge and Trinity chipsets will support Quad-channel memory and if it will realistically mean better performance (specifically for integrated graphics!)

 

[Blain]

2 x 8GB

 

[ncalipari]

But ncalipari, Z68 doesn't support quad-channel memory,

Even with a single channel memory you can end up with a busy bus. It really doesn't matter in typical workload, still theoretically is better to use all the data lanes, rather than leave some unused.

 

[eztarget]

Unless you plan on running crazy applications 16GB of memory should be plenty. Go the cheaper route and get 4 x 4GB and spend the money you save on something else like a bigger SSD drive!

I'm running huge Oracle databases on Solaris/Linux machines with 16GB of RAM.

 

[Herald85]

I'm not a true RAM expert but from what I understand it would take a typical dualcore at 100% load to IO saturate non-ECC dualchannel memory @ 1333Mhz. So yes, in theory certain applications might benefit from 4x2GB but I don't think anyone who really needs memory bandwith would use s1155. Plus, if the memorycontroller is not configured to receive extra juice it's even likely it will decide on it's own to losen (loosen? spelling!) timings.

As far as stability that is typically for overclocking. For example:
4x2GB @ 1333 will usually not be unstable with a stock 2600k, 4x2GB @2133Mhz combined with a 2600k @ 4.8Ghz does become unstable (personal experience).

EDIT: Just to be clear, I have 2x4GB myself in my pc and that is what I recommend for most builds. If I had unlimited money I would get 4x8GB though ;-P

 

[poohbear]

if you're overclocking definitely 2 Ram sticks. 4 ram sticks causes all kinds of headaches with overclocking.

 

[Kenmitch]

I disagree with herald when he says that 2 modules have better stability. The additional load on the memoty controller is negligible given the today technology, anyhow with 4 modules you have:

It goes beyond the onboard memory controller. Filling up all the memory slots also puts more strain on the motherboard at the same time. Not always but sometimes the combination of the 2 will reduce stability and limit your overall overclock. It's a YMMV type of thing just like overclocking in the first place.

OP what do you plan on doing with your rig that you think you need 16gb of memory?

 

[ncalipari]

It goes beyond the onboard memory controller. Filling up all the memory slots also puts more strain on the motherboard at the same time. Not always but sometimes the combination of the 2 will reduce stability and limit your overall overclock. It's a YMMV type of thing just like overclocking in the first place.

In speaking from the point of view of someone who doesn't overclock: do you think that using more memory modules on a good quality motherboard with a good quality PSU could reduce the reliability of a MB? do you have any evidence of that?

I'm genuinely interested.

 

[Coup27]

2 x 8GB

+1.

 

[Kenmitch]

In speaking from the point of view of someone who doesn't overclock: do you think that using more memory modules on a good quality motherboard with a good quality PSU could reduce the reliability of a MB? do you have any evidence of that?

I'm genuinely interested.

Well as long as you throw in some good quality memory at the same time I would not see any issue running at stock speeds. Although to be fare with this statement it could come down to Corsair = no go, G-skill = works great or visa versa.

The thing to remember is even tho you choose high quality parts there still is a chance of full or partial defectiveness. This may not be noticed running stock speeds but when overclocking it is. This also could not be noticed when running with 2 sticks but is running with 4 sticks. Same goes with running with 1 video card vs 2 cards. It's a YMMV thing.

If I needed 16gb's of memory I'd shop for a 8gb x 2 kit and not a 4gb x 4 kit to eliminate the possibility that I may have issues with stability. Ram is cheap these days anyways and it doesn't make sense to take the risk of having issues while only saving a couple of bucks in the end.

 

[bryanW1995]

Future upgradeability or reliability and performance?

I disagree with herald when he says that 2 modules have better stability. The additional load on the memoty controller is negligible given the today technology, anyhow with 4 modules you have:

1) Higher reliability, as the failure of a module will only compromise 25% of your memory and not 50%

2) Lower cost: 4 gb modules are much cheaper

3) Higher performance: it's less likely that a module can be busy. Don't expect huge improvements.

This is just plain wrong. Stability is clearly compromised by adding more ram as evidenced by the greater difficulty in overclocking with more than 2 sticks installed. The only correct part of this statement is that the 2x8 would probably cost more, but the OP specifically said that cost wasn't an issue for this discussion.

In speaking from the point of view of someone who doesn't overclock: do you think that using more memory modules on a good quality motherboard with a good quality PSU could reduce the reliability of a MB? do you have any evidence of that?

I'm genuinely interested.

I do. I could never get stable above 3.9 with 3 sticks in my i7 920 rig, but with 2 I could run all day long at 4.2 (as long as I could stand the noise of the case fans on high).

 

[Kristijonas]

The information of IVB and Trinity supporting quad-channel memory is yet to be confirmed or denied... anyone?

 

[Zoom123]

OP what do you plan on doing with your rig that you think you need 16gb of memory?

It will be used for many things, but the reasons I decided to go with 16GB are

(1) I will do some rendering and I might need more than 8GB

(2) RAM is cheap these days. When I made my current system 5 years ago I spend over $200 for 2GB. Recently I wanted to upgrade with another 2GB, but I was told that adding 2 more sticks of a different brand (I couldn't find the exact same RAM now) could compromise my overclocked system which was running stable for all these years. So for my new system I decided to better add more memory than I need and not to worry about upgrading it in the future.

Could adding 2x8GB instead of 2x4GB RAM result in lower overclock for an i7 2600k? I am aiming to something about 4.5GHz, so nothing too extreme.

 

[Kenmitch]

Could adding 2x8GB instead of 2x4GB RAM result in lower overclock for an i7 2600k? I am aiming to something about 4.5GHz, so nothing too extreme.

Nice to see somebody whom has shopped memory back in the day when it was trully expensive

If it was me I'd buy the 2 x 8gb sticks if I thought I'd need more than 8gb's or ram. I'd see no reason why it would limit your overclock. The important thing is quality of the ram and I guess the occasional this MB doesn't like that ram senario. Just figure out which ram you want and then search for compatability issues.

 

[TemjinGold]

OP: Aside from cost and maybe compatibility with older boards, there is NO advantage to having 4x4.

 

[bryanW1995]

The information of IVB and Trinity supporting quad-channel memory is yet to be confirmed or denied... anyone?

skt 2011 cpus like SB-E and, in the future, IVB-E, support quad-channel memory. I'm not aware of any plan to attempt to get the skt 1155 sb's to support anything more than dual channel.

 

[bryanW1995]

It will be used for many things, but the reasons I decided to go with 16GB are

(1) I will do some rendering and I might need more than 8GB

(2) RAM is cheap these days. When I made my current system 5 years ago I spend over $200 for 2GB. Recently I wanted to upgrade with another 2GB, but I was told that adding 2 more sticks of a different brand (I couldn't find the exact same RAM now) could compromise my overclocked system which was running stable for all these years. So for my new system I decided to better add more memory than I need and not to worry about upgrading it in the future.

Could adding 2x8GB instead of 2x4GB RAM result in lower overclock for an i7 2600k? I am aiming to something about 4.5GHz, so nothing too extreme.

One thing to keep in mind is that cost truly is a factor here. I haven't checked relative prices recently, but I'd guess that you're probably looking at $80-$100 for 4x4 gb and probably double that for 2x8 gb. If there is that much of a delta in price, I'd probably cheap out and grab the 4x4 kit. Keep in mind that if you have 4 sticks of ram in dual channel mode and one of the sticks goes out, your computer will still run in dual channel mode for the first 8 gb and will only drop to single channel if you needed more than 8gb for something. So if you lost one of the 4gb modules you'd probably still be ok at 12gb at least, and that saved money would put you that much closer to the next big upgrade, a better mobo/video card/cpu, etc.

edit: wow, I just checked out newegg. Here's the list of 4x4 and 2x8 kits sorted by price:

http://www.newegg.com/Product/Produc...4%20x%204GB%29
$75 for a decent set of gskill ddr3 1333, $80 if you want 1600

http://www.newegg.com/Product/Produc...2%20x%208GB%29
$100 for what looks like the same ram at ddr 1333, but price jumps to $150 for ddr 1600


From looking at that I'd definitely go with a 2x8 kit if you're ok with ddr 3 1333, and I'd probably get the 4x4 if you decide to go with ddr 3 1600.

 

[mv2devnull]

It's interesting how the guidelines for "work CPU" differ. Westmere 3-channel CPU's. Sure, they come with ECC RAM and offer no overclocking. With them you can put three modules and you stay at advertized 1333 MHz. Make it six and the memory controller throttles to 1066MHz. Fill up to full nine modules and watch 800MHz memory speed. While such safeguarding when there are more than one module per channel might only apply to these Nehalem generation Xeons, one cannot but think that maybe the desktop CPU's face some challenge too in similar situation.

Thus, with no hard facts:
2 x 8GB

 

[Edrick]

I went with the 2x4 setup (months ago) instead of 4x2. The only reason I did this was because I planned on upgrading to x79 and wanted to use the same memory.

With all 4 slots filled, I can not run a 2133 even though my memory is rated as such. I can easily run at 2133 with only 2 slots filled (all 4 memory dimms have been tested fine). So if I was going to stay with dual channel memory, I would go 4x2 or 8x2.

 

[greenhawk]

3) Higher performance: it's less likely that a module can be busy. Don't expect huge improvements.

actually, it is lower. The memory bus is a shared communications path. It is not possible to interleave data requests to the same memory chip or when on the same memory channel.

What about IVB and Trinity? Will they support quad-channel memory?

IVB will still be the same socket as SB, so dual channel. IVB-E will be quad, but it will be s2011 (like SB-E).

Trinity is too far out to be 100% sure, but my money would be dual. It adds cost going higher and most markets are not interested in that.

 

[bryanW1995]

Thats a good point, maybe if you get the 4x4 kit go for the ddr3 1600 kit but run it at ddr 3 1333, instead.