Connect Optane 905p to CPU or to MB chipset PCIe slot?

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JcRabbit

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So, I just got my new system: 4K monitor, Intel 9900K, Asus Maximus Formula XI, 32GB RAM, Asus Strix 2080ti, Intel Optane 905p 980GB NVMe, Samsung 970 EVO 2TB M2.

Currently the Optane is placed in the lower x16 PCIe slot that is connected to the motherboard chipset, running at x4 mode as it should (SATA ports 5 & 6 are disabled).

The big question is: is it worth connecting the Optane to the CPU PCIe lanes instead of to the MB PCIe lanes? Has anyone already tried this or has any data on it? Searching the net got me a lot of 'blah blah' but no hard facts. :)

I know that by doing this the 2080ti will go from x16 to x8 mode, what I don't know is if the performance increase (?) of connecting the Optane directly to the CPU is worth the trade-off (at the very least there should be less latency, and it does not have to share bandwidth with other MB peripherals).

The only reason I haven't tried this myself yet is because to pull this off I will have to install a riser cable that was originally intended for the graphics card: the Strix 2080 ti is a MONSTER card, which means putting the Optane next to it would make BOTH cards run extremely hot due to lack of clearance between the two (as it is the Optane already runs at 45C *idle*). So my solution would be to use the riser cable and the graphics card mount that came with my case (a Cooler Master C700M) with the Optane instead of the graphics card it was intended for. This would allow me to connect the Optane to the second CPU x16 PCIe slot while still having it far enough from the graphics card not to have it overheat while gaming.

Because of clearance issues with the mount and the graphics card height, I just don't feel like going through all the work of installing the mount and the riser cable, etc, only to have negligible gains in the end, if any - and then having to undo the whole thing. So, if anyone knows anything about this before I take the plunge, I would really appreciate the info. :)
 
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I doubt you'll notice the difference either way. So just install it whichever is easiest.
 
daglesj said:
I doubt you'll notice the difference either way. So just install it whichever is easiest.
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Thanks for the reply! Just because you don't 'feel it', doesn't mean it isn't there though. :)

Plus, keep in mind that the Optane's strong point is 4K reads and writes, this is what makes it stand head and shoulders above the other SSDs. I would thus imagine that the lower the latency is, the more responsive the OS will be/feel (but, ah, as you pointed out, it might 'be' but not 'feel' eheh).

The Optane is already installed in the PCIe slot connected to the motherboard chipset and performance in Windows 10 is, of course, great. The question is if it can become even better - I got the idea to connect it directly to the CPU PCIe lanes after seeing some CrystalDiskMark results that seemed to show a bit more through-output than the results I was getting.

It only occurred to me later that those results might be pre-Specter and pre-Meltdown patches.
 
Leave it as you mounted it, not worth to have the gpu runnign hotter, you will lose on the boost clocks and marginally will lose a little bit on 8x, now i don't know why you bought a 905 but to me its not worth the money on a gaming pc, the 970 should take care of everything fine.
 
Abula said:
Leave it as you mounted it, not worth to have the gpu runnign hotter, you will lose on the boost clocks and marginally will lose a little bit on 8x
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Well, that's how I left it, at least for now (busy installing some Cooler Master ARGB fans, waiting for extension cables from Amazon, overclocking the system so it remains stable even in Prime95 small FFT without melting the 9900K, etc)... couldn't even get a straight answer from Intel's own techs on the Intel forums about this either.

My main concern is the PCIe riser cable - it's one thing to have signal problems connecting to a GPU, quite another connecting to your main system drive, especially one as fast as the Optane. Despite daily backups, I'm not very interested in corrupting the OS or any of the data in the drive.

I suppose I could simply plug it directly to the CPU slot to for a while, just to check for any performance differences and thus answer my own question. Can't believe no one else seems to have tried to make this comparison before though.

Abula said:
now i don't know why you bought a 905 but to me its not worth the money on a gaming pc, the 970 should take care of everything fine.
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Because this is not JUST a gaming PC. :)

What I was most interested in was in the 4K performance and IOPS of the Optane (which translates to 24/7 every day performance rather than mostly when transferring large files)- no other NVMe SSD can currently beat that.

I was also interested in a system that would last me 4-5 years like the previous one did without becoming obsolete (previous one had two Intel SSDs in a RAID 0 array for the system drive, 16GB of RAM and an Intel 3770K overclocked to 4.5GHz - still a pretty fast system even by today's standards).
 
JcRabbit said:
What I was most interested in was in the 4K performance and IOPS of the Optane (which translates to 24/7 every day performance rather than mostly when transferring large files)- no other NVMe SSD can currently beat that.
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Really comes down into what you will do with it, i own a 900p and 905p, for editing they are really nice even as a cache for a server seems a good investment, but anything else, any ssd even sata are fine.

JcRabbit said:
I was also interested in a system that would last me 4-5 years like the previous one did without becoming obsolete (previous one had two Intel SSDs in a RAID 0 array for the system drive, 16GB of RAM and an Intel 3770K overclocked to 4.5GHz - still a pretty fast system even by today's standards).
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Dont count on it, if anything right now we are on CPU war, with Ryzen 7 leaks showing some very nice CPUs, we are very likely to see improvements more than last year, specially with 12/16 cores on main stream, given that its not for everybody, for someone that needs editing or rendering.... sweat times. Im currently building on 9900k and a taichi, but i dont think that setup will compete well with in the year, but will see.
 
Abula said:
Dont count on it, if anything right now we are on CPU war, with Ryzen 7 leaks showing some very nice CPUs, we are very likely to see improvements more than last year, specially with 12/16 cores on main stream, given that its not for everybody, for someone that needs editing or rendering.... sweat times. Im currently building on 9900k and a taichi, but i dont think that setup will compete well with in the year, but will see.
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Well, depends on what you do with it, as you said. Alas, most applications (and most tasks) are still single threaded, so for those it really doesn't matter how many cores a CPU has, but rather how fast EACH core is. And, for the moment at least, it seems we are stuck with 5Ghz for a long time to come due to power and heat dissipation physical limits.

Evolution seems to have taken us as far as we can go, CPU wise - what we need now is a revolution. :)

That has already happened with storage, when we switched from rust to flash memory. Perhaps the next step is RAM itself - imagine how much faster a system would be if RAM could run almost as fast as L1 caches currently do (but still costing about the same per MB it does now, of course, lol). :)
 
You'll still be looking at KBps performance when you copy that folder of 80000 microfiles...;)
 
Ok, for the sake of anyone who might be wondering the same thing as me and runs into this thread in the future:

I tried it and it's not worth it. At all.

As an Intel tech correctly pointed out, regardless of anything else the limits are in the drive itself.

According to CrystalDiskMark 6.0.2 x64, there was literally no difference in terms of Q32T1 sequential reads and writes (2670 MB/s read, 2360 MB/s write).

If anything, 4K writes were actually WORSE with the Optane connected to the CPU PCIe lanes (4KiB Q8T8, CPU: 850 MB/s, PCH: 1060 MB/s - 4KiB Q32T1, CPU: 160 MB/s, PCH: 190 MB/s, all other results were basically the same).

Even copying a 40 GB file from my Samsung 970 2TB M2 drive to the Optane showed no improved performance, the opposite in fact: with the Optane connected to the CPU lanes, I got a max of 1.8 GB/s. With the Optane connected to the PCH, I got 2 GB/s.

These results are all with the drive connected directly to the PCIe slots.

I also tried it with the riser cable (just to see what the system would look like with the drive vertical) connected to the PCH PCIe slot. I can't be sure because results with AS SSD Benchmark were all over the place (I used AS SSD Benchmark for this, unfortunately) but it *seemed* like the riser cable (shielded) made sequential reads and writes WORSE by about 250 KB/s. Guess the extra distance signals need to travel does have some influence.

I didn't like the look anyway (the graphics card holder with the drive in it partially blocked the view to the graphics card and the motherboard, plus it made the inside of the system look more cluttered than before), so I ended up reverting everything to how it was previously. Well, at least I tried. :)

If anyone would like to see pictures of this, just let me know.
 
Thought so. Thanks for following up.

Folks are forgetting that things are getting so fast now that any differences/improvements really have to be a quantum leap to be noticeable. It's kind of exponential now.

20 years ago getting an extra 5-10 frames was a real deal breaker. Getting an extra 30MBps would be amazing.

Now you wouldn't notice it. You'd need ten times that to make it worth getting out of bed.
 
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So very true!

I still remember when the next CPU generation was measured in jumps from 33 Mhz to 50 Mhz (486 DX-33 to 486 DX2-50) and that puny 17 Mhz jump would make a VERY REAL difference (my very first CPU was a Z80 on a ZX Spectrum running at 3.5 Mhz). We are talking Mhz here, not Ghz!

Now we can't even feel the difference when we overclock by another 100-200 Mhz! :)

Most people these days have no idea how far we came since the 80's in terms of computer power, and how quickly we did it. I remember staring at an Intel 8088 running at 4.77 Mhz on an IBM PC slowly redrawing the screen *character by character* (we are talking *characters* here, NOT pixels!). VGA (640x480) was not even a thing back then.

Just occurred to me you can also extrapolate this into real life (lol): the further down a rabbit hole you go, the more and more stimuli you need to actually feel something again. Guess the trick in life is to stay where small 'Mhz jumps' still matter. ;-)
 
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