The Kits and The Markets

In our Haswell DDR3 scaling article, we introduced the concept of a Performance Index in order to compare memory kits of different frequencies and latencies against overall performance. The Performance Index is calculated by the rated speed divided by the CAS latency such that:

Performance Index = Frequency / CL

At the time it came across as a good indicator of performance when buying from the shelf, although most companies do not particularly advertise the latencies on the package. Our conclusion for DDR3 on Haswell was that the higher the Performance Index the better, although with two potential options close together, the one with the higher frequency is the better choice. So for example, when given DDR3-2133 C10 (PI of 213) against DDR3-1866 C10 (PI or 187), the first one should be chosen. However with DDR3-2133 C10 (PI of 213) and DDR3-2400 C12 (PI of 200) at the same price, the results would suggest the latter is a better option.

One of the big issues that the Performance Index does not take into account is the price, which fluctuates weekly depending on DRAM supply but also the capabilities of a kit through rarity. When purchasing memory ICs from the big three (Samsung, SK Hynix, Micron), the chips themselves are only rated at a basic speed and it is up to the module manufacturer to do further binning to find the best silicon for the high speed memory kits. As a result many of these companies will bid on certain batches with a history of high performance, and then the extra time required to separate the good chips from a batch adds into the high cost of the top frequency kits. Usually frequency defines the difficulty, rather than the sub-timings and latency because frequency is a defining factor.

When it comes to DDR4, we will be taking a similar broad approach to kit designation, taking the Performance Index of each memory kit in each benchmark and attempting to find a correlation.

The Market

At launch, DDR4 kits had the obvious premium of being a new technology as well as being is short supply due to Intel moving up the date for release. The prices at this time, as we reported, were the equivalent to $213 for a 4x4GB 2133 C15 kit going through $300 for a 4x4 GB 2666 C15 up to $413 for 4x4GB 3000 C15. Based on these numbers it would seem that the high end modules have come down in price quickly, but the lower range products have stayed similar. We took a range of pricing from Newegg to see the effect of being at market for just over six months has done.

The cheapest standard kit of 2133 C15 4x4 GB comes in at $200. The best kit in this layout would be towards the bottom left, as indicated by the performance index in each square:

Here I have marked four areas, representing the low end memory in orange, the more standard in white, the performance modules in green and the super-high performance in dark green. There are currently no modules in that last group, going through all the pricing from 2x8GB kits to 8x8GB kits:

The lowest price per GB is at $387 for 4x8GB of DDR4-2133 C15, at $12.09 per GB, compared to $1800 for 8x8GB of 2800 C16 which makes out to $28.13 per GB.

The interesting segments based on price alone that catch my in that case are:

4x4GB DDR3-2133 C13 for $213
4x8GB DDR3-2133 C13 for $400
At this point, a CAS latency below 15 is something of a novelty. It seems a little more esoteric than usual, as none of the manufacturers we spoke to even considered sampling us something of this nature. I would be interested to actually see how it performs.
4x4GB DDR4-2666 C13 for $290
4x4GB DDR4-3000 C15 for $300
I picked both of these based on the closeness of price and on Performance Index. The latter kit is something we have in for review, but similar to the previous kits listed, a CAS latency of 13 is an interesting element to the equation.
4x8GB DDR4-2800 C15 for $510 Measuring up at nearly $16 per GB, this kit mixes the elements of on-paper specifications, density and price for a nice X99 system.

The Kits

For this roundup and subsequent reviews, we received kits from almost every major memory manufacturer. G.Skill, Corsair, ADATA and Crucial were all willing to send various speeds and densities of memory, ranging from the basic 4x4 GB of DDR4-2133 C15 to 8x8GB of DDR4-2133 C15, or 8x8GB of DDR4-2400 C16 to 4x4GB of DDR4-3200 C16.

The main conclusions from this testing will be from the 4x4 GB modules in order to keep consistency, however the 4x8 GB and 8x8 GB results will be included for comparison. Larger modules (and more modules in a kit) tend to lead to relaxed sub-timings in order to ensure full compatibility with all CPUs in all motherboards. This means that in synthetic testing we may end up with some slightly different results, although this may differ in real-world tests.

Another point to note is module compatibility. When DDR4 was first launched with Haswell-E in September 2014, compatibility issues were a problem. Intel had moved up the time of the launch from mid-September to early September very late in the day, leaving memory vendors to scramble kits to market. This gives them a shorter time to work with ASUS, GIGABYTE, MSI and ASRock in order to insure no issues when working with motherboards, especially with high end memory. Due to this shortened timeframe there were some issues to begin with but these should have been ironed out since. Also on the high speed memory front, it would seem that early motherboard BIOSes were also unable to cope with the higher speed, higher density memory kits. Therefore it is important to make sure that all BIOSes are up to date when buying the expensive memory sets.

DDR4 Module Comparison
  SKU Kit Size Kit Speed Sub-Timings Voltage PI
Corsair CMD16GX4M4B3200C16 16 GB (4x4) DDR4-3200 16-18-18 2T 1.35 V 200
G.Skill F4-3000C15Q-16GRR 16 GB (4x4) DDR4-3000 15-15-15 2T 1.35 V 200
G.Skill F4-2800C16Q-16GRK 16 GB (4x4) DDR4-2800 16-16-16 2T 1.20 V 175
G.Skill F4-2666C15Q-16GRR 16 GB (4x4) DDR4-2666 15-15-15 2T 1.20 V 177
Crucial BLS8G4D240FSA 16 GB (4x4) DDR4-2400 16-16-16 2T 1.20 V 150
G.Skill F4-2133C15Q-16GRR 16 GB (4x4) DDR4-2133 15-15-15 2T 1.20 V 142
ADATA AX4U2400W8G16-QRZ 64GB (8x8) DDR4-2400 16-16-16 2T 1.20 V 150
Corsair CMV8GX4M1A2133C15 64GB (8x8) DDR4-2133 15-15-15 2T 1.20 V 142
 

The memory in this test is as follows, starting with the 4x4GB kits and fastest/most expensive:

DDR4-3200 16-18-18 2T 4x4 GB 1.35 V Corsair CMD16GX4M4B3200C16, PI of 200
$746 on Amazon
$685 on Newegg

DDR4-3000 15-15-15 2T 4x4 GB 1.35 V G.Skill F4-3000C15Q-16GRR, PI of 200
$436 on Amazon
$300 on Newegg

DDR4-2800 16-16-16 2T 4x4 GB 1.2 V G.Skill F4-2800C16Q-16GRK, PI of 175
$305 on Amazon
$270 on Newegg

DDR4-2666 15-15-15 2T 4x4 GB 1.2 V G.Skill F4-2666C15Q-16GRR, PI of 177
$290 on Amazon
$250 on Newegg

DDR4-2400 16-16-16 2T 4x4 GB 1.2 V Crucial BLS8G4D240FSA.16FAD, PI of 150
$180 on Amazon

DDR4-2133 15-15-15 2T 4x4 GB 1.2 V G.Skill F4-2133C15Q-16GRR, PI of 142
$315 Amazon
$250 Newegg

For good measure, we also have the following kits for testing:

DDR4-2400 16-16-16 2T 4x8 GB and 8x8 GB 1.2 V ADATA AX4U2400W8G16-QRZ, PI of 150
$400 for 4x8GB

DDR4-2133 15-15-15 2T 4x8 GB and 8x8GB 1.2 V Corsair CMV8GX4M1A2133C15-ESM, PI of 142
$120 per module

We also have more kits from Crucial, Corsair, G.Skill and KLEVV incoming for when we tackle individual reviews. The purpose of this scaling piece is merely to demonstrate the general effect of speed across the modules currently on the market. As mentioned, some of those kits with a CL of less than 15 look interesting, so I will have to give Mushkin a call or get a contact at Kingston.

Test Setup

Test Setup
Processor Intel Core i7-5960X ES, 8C/16T overclocked to 4.0 GHz
Motherboards ASUS X99 Deluxe
Cooling Cooler Master Nepton 140XL
Power Supply OCZ 1250W Gold ZX Series
Memory Corsair DDR4-3200 16-18-18 4x4GB, CMD16GX4M4B3200C16
G.Skill DDR4-3000 15-15-15 4x4GB, F4-3000C15Q-16GRR
G.Skill DDR4-2800 16-16-16 4x4GB, F4-2800C16Q-16GRK
G.Skill DDR4-2666 15-15-15 4x4GB, F4-2666C15Q-16GRR
Crucial DDR4-2400 16-16-16 4x4GB, BLS8G4D240FSA
G.Skill DDR4-2133 15-15-15 4x4GB, F4-2133C15Q-16GRR
ADATA DDR4-2400 16-16-16 8x8GB, AX4U2400W8G16-QRZ
Corsair DDR4-2133 15-15-15 8x8GB, CMV8GX4M1A2133C15-ESM
Memory Settings XMP
Video Cards MSI GTX 770 Lightning 2GB (1150/1202 Boost)
Hard Drive OCZ Vertex 3 256GB
Case Open Test Bed
Operating System Windows 7 64-bit SP1
DDR4 Haswell-E Scaling Review Enabling XMP
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  • jabber - Friday, February 6, 2015 - link

    Well I've added into my T5400 workstation USB3.0, eSATA, 7870 GPU, SSHD and SSD. I haven't added SATA III as its way too costly for a decent card, plus even though I can only push 260MBps from a SSD, with 0.1ms access times I really can't notice in real world. The main chunk of the machine only cost around £200 to put together. Reply
  • Striker579 - Friday, February 6, 2015 - link

    omg those retro color mb's....good times Reply
  • Wardrop - Saturday, February 7, 2015 - link

    Wow, how did you accidentally insert your motherboard model in the middle of the word "provide"? Quite an impressive typo, lol Reply
  • msroadkill612 - Saturday, September 2, 2017 - link

    To be the devils advocate, many say there are few downside for most using 8 lane gpu vs 16 lanes for gpu.

    if nvme an ssd means reducing to 8 lanes for gpu to free some lanes, I would be tempted.
    Reply
  • FlushedBubblyJock - Sunday, February 15, 2015 - link

    Core 2 is getting weak - right click and open ttask manager then see how often your quad is maxxed at 100% useage (you can minimize and check the green rectangle by the clock for percent used).

    That's how to check it - if it's hammered it's time to sell it and move up. You might be quite surprised what a large jump it is to Sandy Bridge.
    Reply
  • blanarahul - Thursday, February 5, 2015 - link

    TOTALLY OFF TOPIC but this is how Samsung's current SSD lineup should be:

    850: 120 GB, 250 GB TLC with TurboWrite

    850 Pro: 128 GB, 256 GB MLC

    850 EVO: 500/512 GB, 1000/1024 GB TLC w/o TurboWrite

    Because:
    a) 500 GB and 1000 GB 850 EVOs don't get any speed benefit from TurboWrite.
    b) 512/1024 GB PRO has only 10 MB/s sequential read, 2K IOPS and 12/24 GB capacity advantage over 500/1000 GB EVO. Sequential write speed, advertised endurance, random write speed, features etc. are identical between them.
    c) Remove TurboWrite from 850 EVO and you get a capacity boost because you are no longer running TLC NAND in SLC mode.
    Reply
  • Cygni - Thursday, February 5, 2015 - link

    Considering what little performance impact these memory standards have had lately, DDR2 is essentially just as useful and relevant as the latest stuff... with the added of advantage of the fact that you already own it. Reply
  • FlushedBubblyJock - Sunday, February 15, 2015 - link

    If you screw around long enough on core 2 boards with slight and various cpu OC's with differing FSB's and result memory divisors and timings with mechanical drives present, you can sometimes produce and enormous performance increase and reduce boot times massively - the key seems to have been a differing sound in the speedy access of the mechanical hard drive - though it offten coincided with memory access time but not always.
    I assumed and still do assume it is an anomaly in the exchanges on the various buses where cpu, ram, harddrive, and the north and south bridges timings just happen to all jibe together - so no subsystem is delayed waiting for some other overlap to "re-access".

    I've had it happen dozens of times on many differing systems but never could figure out any formula and it was always just luck goofing with cpu and memory speed in the bios.
    I'm not certain if it works with ssd's on core 2's (socket 775 let's say) - though I assume it very well could but the hard drive access sound would no longer be a clue.
    Reply
  • retrospooty - Thursday, February 5, 2015 - link

    I love reviews like this... I will link it and keep it for every time some newb doof insists that high bandwidth RAM is important. We saw almost no improvement going from DDR400 cas2 to DDR3-1600 CAS10 now the same to DDR4 3000+ CAS freegin 80 LOL Reply
  • menting - Thursday, February 5, 2015 - link

    depends on usage. for applications that require high total bandwidth, new generations of memory will be better, but for applications that require short latency, there won't be much improvement due to physical restraints of light speed Reply

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