DFI UT X58-T3EH8 continued - Part 2

[v_parrello]

800MHZ was the norm at the start av i7 C0, but i7 has evolved and most D0's will do @4.2-4.4GHZ 24/7, and this is the BCLK210 territory. 840MHZ has become the "not so nice an round" number that creates a big RAM-dilemma (many sticks can't run at this speed even with higher voltages). I guess many of these "strange" stability problems starts when people try to push the RAM over it's limits.

imho is not only RAM issues, I think these problems are related to CPU Integrated Memory Controller and QPI bus frequency.

Not all the CPU are abe to run with uncore > 3.6 GHz and/or QPI bus strongly overclocked: BCLK>190 MHz and then QPI bus >190x18=3420 MHz.

[Sam_oslo]

imho is not only RAM issues, I think these problems are related to CPU Integrated Memory Controller and QPI bus frequency.

Not all the CPU are abe to run with uncore > 3.6 GHz and/or QPI bus strongly overclocked: BCLK>190 MHz and then QPI bus >190x18=3420 MHz.

I agree, depending of the CPU-batch, the QPI bus can be the problem too, but that's relatively easy to diagnose/fix. On the other hand, many RAM-sticks can limit a good CPU-batch to run at BCLK210 (1680MHZ RAM). This is not so easy to diagnose and people are reporting some "strange" instability problems (it can pass the Memtest, LinX and PrimeBlend, but fails in SuperPI, or other "strange and unheard" problems).

It is not easy to generalize, but I believe many of these "strange" instability problems are rather related to "too high BCLK for the RAM" than for CPU/QPI/Uncroe (but I agree that this problem exists too). After "the dead of the hyper", there not many sticks in the marked that can run stable @1680MHZ (even with unsafe Vdimm).

An easy way to diagnose the QPI-problem can be to run LinX/PrimeBlend with QPI fast mode, disabled.

[Razer(x)]

I agree, depending of the CPU-batch, the QPI bus can be the problem too, but that's relatively easy to diagnose/fix. On the other hand, many RAM-sticks can limit a good CPU-batch to run at BCLK210 (1680MHZ RAM). This is not so easy to diagnose and people are reporting some "strange" instability problems (it can pass the Memtest, LinX and PrimeBlend, but fails in SuperPI, or other "strange and unheard" problems).

It is not easy to generalize, but I believe many of these "strange" instability problems are rather related to "too high BCLK for the RAM" than for CPU/QPI/Uncroe (but I agree that this problem exists too). After "the dead of the hyper", there not many sticks in the marked that can run stable @1680MHZ (even with unsafe Vdimm).

An easy way to diagnose the QPI-problem can be to run LinX/PrimeBlend with QPI fast mode, disabled.

My problem is, for example, that i can't get the pc stable with uncore >3000

[Sam_oslo]

My problem is, for example, that i can't get the pc stable with uncore >3000

If Uncore is your "only" problem, then you can solve it easily. You haven't post any detail screen-shot yet, and it is not easy to guess the rest from your short posts either.

I'm afraid your problems are a bit more than that, but if that's the only problem, then you can use x6 multi on RAM, and have 12x or 14x Uncore, and still be under 3000 even at BCLK210. 14x210=2940 < 3000. We ended up with RAM-settings again?

[Razer(x)]

If Uncore is your "only" problem, then you can solve it easily. You haven't post any detail screen-shot yet, and it is not easy to guess the rest from your short posts either.

I'm afraid your problems are a bit more than that, but if that's the only problem, then you can use x6 multi on RAM, and have 12x or 14x Uncore, and still be under 3000 even at BCLK210. 14x210=2940 < 3000. We ended up with RAM-settings again?

In fact now i'm stable at 200x18 with uncore 2800mhz with 1.24v (the lowest vtt, my mobo has a positive drop of 0,03v)

Ok, i don't really care about the uncore, but 'cause of this mobo i can't get my pc stable with ram >1400 mhz

[Sam_oslo]

What about this one?

I think the main problem to run high RAM frequency is strictly related to uncore frequency and quality of IMC of CPU. There are a lot of RAM in the market that are able to run at high frequencies with really low voltages (all the kits equipped with elpida BBSE).

I won't trust this one for 24/7 use, either the stability (because you have tested the RAM all the way, at least on this screen shot) or the reliability/durability (because your are using VVT>1.35v). But yes you are right, when you get to high speeds (around 2000MHZ) then IMC plays much bigger role than it plays around 1700MZ. You need good CPU-batch to run Uncore >4200MHZ.

I know some sticks can run >1600MHZ, but most of these who are reporting about problems here, are running those "god old first generation 1600MHZ" RAM.

In fact now i'm stable at 200x18 with uncore 2800mhz with 1.24v (the lowest vtt, my mobo has a positive drop of 0,03v)

Ok, i don't really care about the uncore, but 'cause of this mobo i can't get my pc stable with ram >1400 mhz

Maybe your RAM (or CPU or other settings which i don't know much about) are limiting your MB? Uncore is sitting in your CPU, and is more dependent on your CPU-batch than your MB. In these speeds will the MB has almost nothing to say about your Uncore speed.

[Razer(x)]

Maybe your RAM (or CPU or other settings which i don't know much about) are limiting your MB? Uncore is sitting in your CPU, and is more dependent on your CPU-batch than your MB. In these speeds will the MB has almost nothing to say about your Uncore speed.

I don't think so. This kit can easily do 2000mhz CAS8 with 1.65v (2h of memtest passed)

[v_parrello]

I won't trust this one for 24/7 use, either the stability (because you have only the tested GPU-RAM) or the reliability (because your are using VVT>1.35v). But yes when you get to high speeds (around 2000MHZ) then IMC plays much bigger role than it plays around 1700MZ. You need good CPU-batch to run Uncore >4200MHZ.

I know some sticks can run >1600MHZ, but most these who are reporting about problems in this treats are running those "god old first generation 1600MHZ RAM".
....

Sorry what does mean your sentence "because you have only the tested GPU-RAM"? I have tested CPU and RAM not GPU and RAM (OCCT was CPU test with large data set for RAM, and prime was blend test for CPU and RAM).

The test demonstrates RAM could easily run at 2100 MHz with low vdimm voltage, obviously is not for 24/7 use because of high VTT voltage.

Then do you agree with the fact that the problem are not RAM but CPU uncore and IMC?
RAM are able to go over 2100 MHz easily and to be stable, the problem is CPU that are not able to manage so high RAM frequencies because of high uncore and Integrated Memory Controller (IMC) quality that need high VTT voltage to be stable.

The IMC always plays bigger role: there are CPU that are not stable (with prime, linx and similar application), with 3200 Mhz uncore and need a lot of VTT to be stable. Is not a RAM question. The same kit of RAM could be not stable with low VDIMM and low VTT with a CPU at 1600 Mhz and 3200 Mhz uncore, with another CPU the same kit is stable with same settings.

[v_parrello]

....
After "the dead of the hyper", there not many sticks in the marked that can run stable @1680MHZ (even with unsafe Vdimm).
...

What about this one?


I think the main problem to run high RAM frequency is strictly related to uncore frequency and quality of IMC of CPU. There are a lot of RAM in the market that are able to run at high frequencies with really low voltages (all the kits equipped with elpida BBSE).