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DX79SR low RAM performance


Hi everyone.

I'm new to Intel support forum, since I didn't have any issues with Intel boards until this one (or which I couldn't sove by my own knowledge).

I have DX79SR board, 3930K, 16GB kingston 2133 RAM (4x4) and GTX570 (and A bunch of SSD's - no HDD). I use PC for video editing and vas majority of time I render video using NEAT video (very CPU intensive filter for noise reduction which can use CUDA processing too). I upgraded my sistem from Z68/2600K and LOST PERFORMANCE! I'm soo sad.

My issue is slow RAM performace, or Quad vs Dual = the same. It is no difference if put 2 ram inside or 3, or 4, regarding throughput. I do measure performance on 3 different ways: SiSandra2012, AIDA64 and real life rendering speed in one of my application. Please read my background, to understand why I think something is wrong.


NEAT video is very CPU intensive so I upgraded from Q9550 to 2600K. I put it on Z68 (Asus V-PRO) and 1600 Kingston HyperX ram. I overclocked my (24/7 OC was 44) system. Since NEAT video can take advantage of CUDA processing I bought GTX460. It helped just little. few % more using CPU+GPU. I bought 550ti, it was better, but not much. I bought GTX570, it was even less improvement. Funny is that CPU rendered at 9 fps, GPU at 8 fps. But together it was 11 fps maybe. Than I overclocked GPU, and little change was seen (3-5% at 30% GPU overclock). I blamed software.

Than I overclocked RAM to 1866. Boy that was improvement in rendering speed! So I bought 2133 HyperX I have now. Again 15% improvement on rendering speed. Not only CPU and GPU alone performed better, but aggregate performance was much better too. Filter now started to use HyperThreading "virtual cores" too, not only real ones. I saw that GTX570 was not reached its limits yet. So SB-E with 4 channel RAM would rock (I thought).

But when I transplanted RAM and GPU to new PC, rendering speed was much slower than on Z68! CPU did few % better than 2600K (overclocked the same to 44) but that very same GPU performed 30% less than on Z68. Even aggregate rendering speed was now slow as with Z68 with 1600RAM. I tried to everclock RAM and CPU to the limits, but all I can achieve is 90% of performance what my previous Z68 achieved.

Than used AIDA64 and saw the problem. RAM "reading speed" test showed 22000MB/s on X79, but same stick of ram put in Z68 scored at 28.000MB/s. "Writing speeds" are even more different between plaforms. Latency Z68=40ns, Z79=45 (at best). If I calculate this values they reflect the same %-tage in real rendering speed differencies. The speed scores in AIDA are the same if I use two sticks of ram, or 4. But it is halwed if I put inside only one RAM. So what I get on X79 is effectively dual channel, regardless CPU-Z sais Quad. I have RAM in blue slots, and they are QuadKIT.

Than I downloaded SISoftwareSandra2012. Now this software showed 26GB/s on Z68, but 50GB/s on X79. With two sticks half of that. Ok, that proves I have quad channel engaged and it works (in theory). But in real life is slower than Z68's dual channel.

Because I needed to pay for new CPU and motherboard, I sold Z68+CPU+cooler. SO I can+t test any moore. But as I have well documented all my previous sistems, in real life all my work is now slower 25% than on Z68 (Because SB-E does not want to be stable at same speeds than 2600K + it does overheat sooner). Before all 4 cores was mostly at 100% when rendering. Now 6 cores are anywhere from 30-70%, and only Prime95 make them 100%.


So clearly RAM is NOT capable of deliver enough data to both GPU and 6 cores of CPU, not mentioning virtual cores, to be 100% occupied. Or bottleneck is maybe elsewhere??

If anybody knows what solution might be, I woul give him a hug:) Intel claim great memory performance boost with SB-E, but all I can see is lees than dual channel with exact same RAM (and XMP settings + tightened timings). I hoped for at least 25% improvement if not 50%, over 2600K on Z68. But -10% is a big shock.

Sorry for long post, please take my opology for my english too (if needed).


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4 Replies
Valued Contributor III

Well, the AIDA64 memory test is crap, it`s create only 2 threads, so all systems for it are dual-channel. My result in Sandra is about 40 GB/s on DX79SR+3960X+4xKingston HyperX 1600. SB-E platform is good for those who need raw CPU power and/or virtualization, for games and graphics-intensive apps you better look to Ivi Bridge - looks like desktop platform have shorter paths between cores and data, in terms of latency and pipeline depth. Alternatively, probably you can achieve a 10% gain if change Intel MB to ASUS-branded one.

Hi, JFFulcrum.

Thanks for reading my post. I concluded the same:

- X79 chipset is obviously slover than Z68 per channel/clock. My Intel board does even not have X79 drivers but C600 !?!

- There is no software right now to gain benefit from quad channel - obviously SANDRA can, but not AIDA and not MY SOFTWARE I work WITH. Even GPU scores less than it was on Z68.

- I'm intel channel partner/system integrator and I'm starting to hate Intel boards slowly: After all years just issues all the time. I'll change motherboard for ASUS.

After ten years I can conlude that Intel =:

- higher cost for less equipped board

- BIOS is often unvorkable out of the box - sometimes only recovery bios was option, since even keyborad was dead.

- drivers are often buggy and cause different problems

- Lame BIOS (back to BISO switch is only bright point only, +marking "changes" in dialog)

- Do not want to be stable at any overclock speed, even slightly (BSOD's), or I can't do it.

- While usually Intel had bunch of FAN headers even on cheap boards, this DX79SR has ONLY 3 of them!

- Issues with drivers - a lot of hassle to be operationable. I must switch off some INTEL services; unless sleep does not work

- Intel Extreme Overclock does not work (and interfere with sleep - BSOD)

- I hat to upgrade firmware for USB3.0 controller, since it did't work at all, and solution was not provided by Intel, but some obscure third party site

- Intel SATA does not recognise BD writer... and so. Had to put it on Marwell.

Intel = good for servers with no overclocking, for years of stable serving. And warranty is it's plus. It is clearly NOT for enthusiasts. As Intel representative said once on Intel channel conference: "We have not much of interest selling desktop boards - we just must have some of them on disposal. Main business are processors".

Since I'm also Gigabyte and Asus dealer, choise will be easy in the future. But still I will be happy for any usefull hint how to squeeze more juice out of that board. I can't overclock even with those presets they are backed in BIOS. Bsod's... Any usefull hints would be apreciated. Because I'm not buying new board tommorow - It's 300 EURos And I must finish projects...



Valued Contributor III

Actually I got memory performance improvements over my previous LGA1366 system in archive management - 7-Zip is really happy with quad-channel. Also QC is good when you must in parallel run some virtual machines while doing usual work - performance hit for desktop is minimal compared to mainstream platforms.


Intel MBs always not been a benchmarks leaders, but had rock solid stability. Now they still not have best performance, and lost stability. DX79SR is my second MB in current system, DX79SI only lasted for four months (i hope it died in agonized death).

Unfortunately, other MB manufacturers are also become much worse, which is ridiculous looking at current prices - for 300 EUR you can by a whole, not bad notebook.


Agree with all.

I started to gain benefit from this 6-core on the old fashioned way, as I did when Pentium D came out and was no apps to know how to multitask: Multitasking MYSELF :-)

Leaving Adobe Media Encoder in the background, now I can design in Photoshop/Corel/Lightroom, Code in Dreamwever, or even do rough editing in Premiere. I see, I need 32GB ram, which is not a problem (beside +100 EUR).

Best regards,