Near term outlook for CPU's that can access 128GB RAM

[Cidona]

Dear Forum,

I would appreciate feedback on the following.

(1) Would I be correct in the following ‘statements’:
(a) If I want to have 128GB of RAM, without going to an 'Xeon type system' then I am required to go to a 6 or 8 core CPU i.e. 2011-v3 socket type?
(b) This is extremely unlikely to change with Skylake/Broadwell releases prior to October/End of year?

(2) It seems the 128GB RAM kits are running @ 2400. Would this speed limit overclocking of the processor? If so, what speed would be anticipated (rock solid 24/7 quality overclock) with 5930K/5960X for a beginer if using decent cooling? (would consider water/liquid though haven’t used before).

 

[Karsten75]

You'd be hard pushed to utilize 128GB of RAM in almost any computing environment I can think of that's not server-based.

Even the high-end Intel Core i7 processors do not support more than 64GB of RAM. The extreme memory configurations require Registered memory to offload some processing to the on-stick memory controller and then you lose a CPU cycle per memory access.

Xeons can't be overclocked and generally do not support memory speeds in excess of 1600MHz without some BIOS tweaking and even then probably not very well or with much effect.

 

[Deuce65]

Dear Forum,

I would appreciate feedback on the following.

(1) Would I be correct in the following ‘statements’:
(a) If I want to have 128GB of RAM, without going to an 'Xeon type system' then I am required to go to a 6 or 8 core CPU i.e. 2011-v3 socket type?
(b) This is extremely unlikely to change with Skylake/Broadwell releases prior to October/End of year?

(2) It seems the 128GB RAM kits are running @ 2400. Would this speed limit overclocking of the processor? If so, what speed would be anticipated (rock solid 24/7 quality overclock) with 5930K/5960X for a beginer if using decent cooling? (would consider water/liquid though haven’t used before).

1a. Well no, you can't. 5930/5960 support 64GB of memory; to do more, you have to go xeon. What is your opposition to using xeon?
1b. Well I can't predict the future. I highly doubt this will change anytime soon though.

2. Since it won't work with the CPUs listed, there is no answer.

 

[Cidona]

Thank you both for your replies!

It seems that these kits are available http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&IsNodeId=1&N=100007611%20600521523%20600563496

My understanding was these were to be for the X99 systems, and that therefore the 2011-v3 processors would work with them. What processors are anticipated to be used with these RAM kits in the next 6 months?

The reason I'm enquiring is I'm working with Navisworks, Revit, AutoCAD, Autosprink... The project I'm finishing up right now has at time used my now 32GB and 14GB Pagefile. Even though it's using Pagefile, it hasn't impacted performance as much as I would have thought. And I'll be fine for finishing out this project as there is only a few more weeks on a year long project.

However, I'm quoting on a project that would be multiple times the project I'm finishing up. Should that project come my way I would anticipate my current system being overwhelmed. The only reason I was 'avoiding' Xeon was that while these programs are using a lot of RAM, they (for most of my commands, etc.) are primarily single threaded. I was therefore hoping to get the best of both worlds by have a platform that would give me 128GB RAM, but that would also have as high a clock speed as feasible.

However, if this project comes in I think the amount of access to RAM will drive purchase decision.

 

[Deuce65]

2011-3 Xeon CPUs is what I imagine those ram kits are for.
In any case though you could get something like a Intel Xeon E5-1650 v3 Haswell-EP 3.5GHz; its single core performance should be virtually identical to that of a 5930k (not OCed though of course) and at the same price point.

 

[Cidona]

My understanding is that you need RDIMM memory for use with Xeons, while these are UDIMMs.

Also, in this article they are using a 128GB in a ASUS X99 Rampage V Extreme, which seems to be an i7 mobo rather than able to use Xeon & i7; so I was presuming they were using an i7. http://www.anandtech.com/show/9188/gskill-announces-16gb-unbuffered-modules-128gb-kit-at-ddr42800

The speed of RAM seems to be slower when using RDIMMS and as you say, the Xeons can't be overclocked. I was hoping to be able to overclock a 5930K up to approx 4.2Ghz while accessing the 128GB of RAM.

 

[Deuce65]

Well I do not know what they did in that article, which lists a Asus X99 Rampage Extreme V as the board and an Intel 5820x as the CPU. But if you go to ASUS' website, they list 64GB as the maximum for that board, and intel of course lists 64GB as the maximum for that CPU. So I'm not sure what is going on there.

 

[Cidona]

Thanks again for the reply Deuce65.

I think the 64GB shown as a limitation for the CPU & that mobo are due to the maximum memory that could have been used with available modules at time of publishing rather than being a 'hard' limitation of the CPU or Mobo. These 128GB kits have only recently started to become available so they probably haven't updated/fully certified product documentation, etc. However I do think that these 128GB memory kits are intended to work with 2011-v3 CPUs.

In that Anandtech article it says "At this point in time, G.Skill is showing that DDR4-2800 with 128GB works with the ASUS X99 Rampage V Extreme, although the XMP profile should allow use on other motherboards. Personally I would suggest that X99 users ensure they have the latest BIOS update before installing these modules, should they have any additional sub-timing parameters needed. I would also expect that as other manufacturers get these modules in to test, validation lists and QVL will be updated."

I'll chase further verification prior to any purchase, etc., but should it be the case that with a BIOS update allows access to the 128GB kits with a 5930K, would the 2400 speed have a impact on the achievable speed of the CPU overclock?

 

[Deuce65]

Well tbh I'm not sure how it is possible to overcome the memory limit with just a bios update, given that the memory controller is built into the CPU. But I don't know enough about it to say.
As for overclocking, at more extreme OCs it can introduce issues yes, but that is extreme, if you are just bumping it up a little bit it won't be an issue. What I mean is, you will be able to OC the CPU regardless of the memory speed. But, it is possible that you might be able to get a tiny bit more out of your CPU OC if the memory isn't OCed at all. In general, I wouldn't worry about it but the extreme benchmarkers might feel different.

 

[Cidona]

Thank Deuce65.

I think I'm closer to a purchase than I thought. I only get to research the hardware stuff when I'm coming up a purchases so I have a bit of catching up to do. I had been considering an i7 4790K, or holding out for the Skylake (seems to be looking at August). However with the i7 4790K and the 1150 socket it seems that they are limited to 4 memory slots and therefore would not be possible for greater than 64GB RAM. Likewise, from what I'm gathering the initial release of Skylake compatible desktop mobos are going to be be 4 memory slots only.

If that's the case then it would seem other than the 2011-v3 or Xeon options, there likely won't be anything that could use 128GB until Broadwell E would come out; which I'm gathering would be end of year at best. That being the case it would make the decision fairly easy to make should this project come in. As while 'suffering' for a month might be feasible, 6 months wouldn't be an option.

 

[Woody1999]

Why couldn't you use the Xeon E5-1650v3? It has great single thread performance and support for 128GB RAM.

Woody

 

[Cidona]

Well Woody1999 the speed of RAM seems to be slower when using RDIMMS and as I understand it, the Xeons can't be overclocked. I was hoping to be able to overclock a 5930K up to approx 4.2Ghz while accessing the 128GB of RAM.

I'm figuring this build could be in the $5K range; and as I mentioned a lot of what these programs do are single threaded. It would kind of 'bum me out' to be dropping that much on a system and to think that at times (i.e. when I'm not utilizing >64GB), that someone with a 4790K system at half the price was getting better performance

 

[Woody1999]

I think it supports non-ECC memory just fine.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Xeon E5-1650 V3 3.5GHz 6-Core Processor ($564.99 @ SuperBiiz)
CPU Cooler: RAIJINTEK AIDOS BLACK 48.6 CFM Sleeve Bearing CPU Cooler ($24.78 @ Amazon)
Motherboard: ASRock X99 Extreme4 ATX LGA2011-3 Motherboard ($193.99 @ SuperBiiz)
Memory: G.Skill Ripjaws 4 Series 128GB (8 x 16GB) DDR4-2400 Memory ($1599.99 @ Newegg)
Total: $2383.75
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-06-13 21:13 EDT-0400

Woody

 

[Cidona]

I thought you were meant to use ECC memory with Xeons. However, if non-ECC can be used, the E5-1650 V3 @3.5 GHz would still be considerable slower than 5930K @ 4.2 GHz for certain aspects that would be desirable to me.

 

[Woody1999]

I thought you were meant to use ECC memory with Xeons. However, if non-ECC can be used, the E5-1650 V3 @3.5 GHz would still be considerable slower than 5930K @ 4.2 GHz for certain aspects that would be desirable to me.

I guess so, but let's hope Intel gets a move on with Broadwell i7s before we fall into the X99 trap.

Woody

 

[Cidona]

I think I might have to 'fall for the X99 trap' . It seems the very recently released 5775C & 5765C might be it for Broadwell mainstream Desktop before the Skylake desktops come out; and that it'll be Q1 2016 before the Broadwell 'E' series comes out.

Even then, I think the Broadwell 'E' is going to use the X99 platform. Which would make it seem that Skylake (E) platform is possibily mid 2017 before having mobos with 8 memory slots. That being the case - to go with 128GB seems to require falling for the 'X99 trap' for nearly the next 2 years. Right?

 

[Karsten75]

My understanding is that you need RDIMM memory for use with Xeons, while these are UDIMMs.

I think (with the emphasis on think) that both UDIMMs and RDIMMs are supported, with UDIMMs mandatory for the higher RAM amounts. I think (that word again) that RDIMMs can support 2x the UDIMM RAM amount.

 

[Cidona]

I'm not 100% on Xeons supporting non-ECC. They might. However on the X99 mobos that show support for i7 and Xeons on the memory section they typically state that ECC UDIMM for the 128GB. Again since these are Non-ECC 128GB kits I think the 64GB limitation was published before the 128GB kits started showing up.

I need to contact the manufacturers (CPU & Mobo) to get clarification as there is indeed a lot of documentation out there stating 64GB maximum supported memory on the 5930K & 5960X as I really would like to be able to get the additional clock speed if it is something that is supported and just that documentation hasn't been widely updated yet.

I'll report on here what they say on the matter. Thanks again for all the input; but I'm just not 100% on things just yet. There are still several aspects that are leading me to believe the 128GB will be supported by 5930K & X99 mobos, but I'm wrong quite a bit so ...

 

[vacaloca]

Dear Forum,

I would appreciate feedback on the following.

(1) Would I be correct in the following ‘statements’:
(a) If I want to have 128GB of RAM, without going to an 'Xeon type system' then I am required to go to a 6 or 8 core CPU i.e. 2011-v3 socket type?
(b) This is extremely unlikely to change with Skylake/Broadwell releases prior to October/End of year?

(2) It seems the 128GB RAM kits are running @ 2400. Would this speed limit overclocking of the processor? If so, what speed would be anticipated (rock solid 24/7 quality overclock) with 5930K/5960X for a beginer if using decent cooling? (would consider water/liquid though haven’t used before).

Might be a bit late for an answer to OP, but not in general. I'm currently running on a system based on an ASUS Rampage V Extreme motherboard with a GSKILL F4-2400C14Q2-128GRK UDIMM memory kit. While it is possible to attain 2400 memory timings, for my particular 5930K CPU it is not particularly stable w/ XMP profile as it's quite taxing on the processor's integrated memory controller (IMC) -- sometimes booting to Windows 7 will hang even after tweaking VCCSA, so for now I am running them at the stock JEDEC 15-15-15-36 2133 speeds and they run just fine.

I haven't tried to overclock the CPU as it already runs about 72 C max during high stress prime95 runs, but I would imagine if you have a decent CPU/cooler and patience it would be possible to do both.

 

[Cidona]

Dear Forum,

I would appreciate feedback on the following.

(1) Would I be correct in the following ‘statements’:
(a) If I want to have 128GB of RAM, without going to an 'Xeon type system' then I am required to go to a 6 or 8 core CPU i.e. 2011-v3 socket type?
(b) This is extremely unlikely to change with Skylake/Broadwell releases prior to October/End of year?

(2) It seems the 128GB RAM kits are running @ 2400. Would this speed limit overclocking of the processor? If so, what speed would be anticipated (rock solid 24/7 quality overclock) with 5930K/5960X for a beginer if using decent cooling? (would consider water/liquid though haven’t used before).

Might be a bit late for an answer to OP, but not in general. I'm currently running on a system based on an ASUS Rampage V Extreme motherboard with a GSKILL F4-2400C14Q2-128GRK UDIMM memory kit. While it is possible to attain 2400 memory timings, for my particular 5930K CPU it is not particularly stable w/ XMP profile as it's quite taxing on the processor's integrated memory controller (IMC) -- sometimes booting to Windows 7 will hang even after tweaking VCCSA, so for now I am running them at the stock JEDEC 15-15-15-36 2133 speeds and they run just fine.

I haven't tried to overclock the CPU as it already runs about 72 C max during high stress prime95 runs, but I would imagine if you have a decent CPU/cooler and patience it would be possible to do both.

Thank you for the insight vacaloca.

The (large) project I was anticipating getting that was prompting me to look at this type of system ended up not coming my way. The projects I have been working on since have been considerably smaller so have been able to work with my existing setup (32GB RAM).
Interesting that your temps are getting up to 72°C at stock clocks. Thought they would have been lower as from what I hear the 5930K is meant to be decent at overclocking. Given that you sprung for the Rampage V Extreme mobo I’d have thought you’d have used a good cooler.
Sounds like a serious machine. Wish you many happy miles with her