LGA2011 Motherboard and memory selection

Toggle sidebar Toggle sidebar
LFaWolf

LFaWolf

Distinguished
Jul 6, 2010
66
0
18,630
Hi everyone, I am currently building a high end system for gaming and a little video editing. I have some questions that I would love to get your feedbacks. I need this machine to last at least 5 years because I will not be able to build or buy for that long :( Long story...

I have already acquired the CPU (LGA2011, i7-3960x) and the power supply (Seasonic X-1250). I plan to OC the CPU to 4 to 4.3 GHz on air but no higher. I play games on 2560x1600, but I also have 3 1920x1080 LCDs sitting around and may switch to 5,760x1080. I am not sure yet. I will definitely get 2 graphics card, but I can't yet decide on either 7990 or GTX Titan, but that is another story. If I get the Titan I may get lucky and sneak in another card a few years down the road if I need the performance.

I already have the following pieces -
CPU: LGA2011, i7-3960x, OC to 4 to 4.3 GHz
CPU Cooler: Prolimatech Megahalems with 2xCougar 120mm PWM fans
Power Supply: Seasonic X-1250
Case: NZXT 810 Switch, Corsair 800D, or Thermaltake Chaser MK-I (yes I got all 3)
SSD: Corsair Neutron GTX 480GB
Everything will be air-cooled and I will not modify the board to use liquid cooling.

Undecided
GPU: 2x AMD7990 or 2x GTX Titan

I have narrowed down the motherboard to the following 4 and a few select memory. I am having a hard time deciding which to buy. All motherboards have 8 DIMMs slots. Yes I need them all.

ASRock X79 Champion LGA 2011
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157318
What I like: Color Scheme, no fan on the chipset, 12 + 2 Power Phase, x16/x16
What I don't like: Warranty 1 year but I think that is a typo. x16/8/8/8 as I prefer x16/x8/x16. Only 1 8-pin CPU plug. Is that enough for my overclock?

ASRock X79 Extreme9 LGA 2011
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157285
What I like: Lots of features, 2x8-pin CPU plugs, 16 + 2 Power Phase, PCI-e x16/0/16/0
What I don't like: Fan on the chipset. I really don't like it, but I can live with it if the board is awesome. PCI-e x8/8/8/8

ASUS Rampage IV Extreme LGA 2011
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131802
What I like: Lots of features, 4-pin + 8-pin CPU plugs, 8-phase CPU power + 3-phase VCCSA + 2+2 phase DRAM power, PCI-e x16/16, x16/8/16; uses 6-pin plug for extra power for PCI-e, so I don't need to plug in a molex just for that.
What I don't like: Fan on the chipset. I really don't like it, but I can live with it if the board is awesome. Some features that I would never use.

MSI Big Bang-XPower II LGA 2011
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130626
What I like: no fan on the chipset, 2x8-pin CPU plugs, 20 Power Phase, PCI-e x16/0/16/0
What I don't like: I don't like the bullets chipset and machine gun heatsinks, but I can live with it. PCI-e x16/8/8/8

If you have any experience with these boards, please speak your mind so I can make a better decision.

As for the memory, I want memory that can run at the rated speed at 1.5V and no more, as I don't want to fry the CPU. Do I really need a Quad Channel memory? I have been thinking about these sets that are certified Quad Channel Kits -
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231525
Buy 2 sets of the followin -
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220699
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231620
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231524

Can they run at the rated speed @1.5V DIMM voltage? It is important to me.

Thanks for any insights or feedbacks in advance!


 
Sort by date Sort by votes
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040
I recently built a Socket 2011 system that I plan to use for somewhere in the ballpark of 5 years (maybe 3 as desktop, then use it to replace my current fileserver).

I got a c60x board and a Xeon CPU, so I can run ECC memory. If you care about system stability, that's the best option. Sadly, you need both a Xeon and a server/workstation motherboard.

Assuming you're going to keep your CPU, then I'd recommend focusing on low-latency memory. Quad-channel is going to have plenty of bandwidth, so you'll probablyl gain more performance by focusing on low latency than on higher-speed. The way to compare latencies of different speed memory is to divide the CAS Latency (also called CL) by the clock speed of the RAM. That gives you the latency in nanoseconds, so you can compare the CL between ram of different clock speeds.
 
Upvote 0 Downvote
LFaWolf

LFaWolf

Distinguished
Jul 6, 2010
66
0
18,630
I believe Gigabyte has the UP5 (?) board that supports XEON and ECC, but I already got the 3960x so I am not even looking at XEON or ECC. I just want it for gaming.

So you are saying, get 1600MHz memory with CAS 9-9-9@1.5V instead of 2133MHz with CAS of 11-11-11@1.5V?
 
Upvote 0 Downvote
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040
Also, some motherboards/CPUs add a couple cycles of latency when you have multiple unbuffered DIMMs/channel. So, that's a disadvantage of filling all 8 RAM slots, as opposed to sticking with one DIMM/slot. But I've also read that the same penalty can be incurred simply by using dual-ranked DIMMs (which nearly all high-capacity DIMMs are). So, maybe it's a moot point. Hard to find concrete info about this, unfortunately.
 
Upvote 0 Downvote
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040
I got a Supermicro board, FWIW. X9SRA

The main thing to look at is the first number (and the speed). That's the CAS Latency. So, CL9 1600 MHz memory has a CAS Latency of 5.625 ns (divide 9 cycles by 1.6 GHz). CL11 2133 MHz memory has a CAS Latency of 5.16 ns. So, even though it's 2 more cycles, the shorter cycle time of 2133 MHz memory means it has a slightly lower latency.
 
Upvote 0 Downvote
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040
BTW, another advantage of the E5-series Xeons is that they officially support PCIe 3.0. I don't know why the non-Xeon Socket-R (LGA2011) CPU's don't, or how much it matters, but I just thought I'd mention that for anyone who's following this discussion.

My E5-1620 Xeon cost about the same as an i7-3820, which is basically equivalent (except for ECC, PCIe 3.0, and a couple of minor features). I don't know how costs compare for the 6-core models. The biggest downside of going the Xeon route is motherboard selection, if you decide you care about ECC.
 
Upvote 0 Downvote
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040
BTW, be sure to get 1.5V RAM. I got burned by using 1.35V RAM that Crucial's web site said was compatible with my mobo. Well, it turns out that the E5 Xeons support it, but only up to 1333 MHz, even if the memory is capable of running much faster than that and coded accordingly. I assume the same applies to the i7-3960x.
 
Upvote 0 Downvote
LFaWolf

LFaWolf

Distinguished
Jul 6, 2010
66
0
18,630


Thanks for the tip! That's great to know. But, won't you be able to raise the voltage of the memory to 1.5V and run the memory at 1600MHz or what it is rated for?
 
Upvote 0 Downvote
bit_user

bit_user

Polypheme
Ambassador
Jan 20, 2010
14,161
5,738
62,040

Perhaps. Not on my motherboard (it's a workstation/server board, meaning not many overclocking features), but perhaps some. But, rather than run the RAM out-of-spec and risk instability, wouldn't it be better to just buy some that's designed to run at 1.5V?
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom