Hi all, and Intel, I hope!
The other day, I recieved a heap of new parts for a mega gaming build, needless to say, it wasn't cheap!
The system components are listed below:
Motherbaord: ASUS ROG Rampage IV Black Edition
CPU: i7 4930K
RAM: 64GB Corsair Vengeance Pro 2400C11R (8x8GB)
Operating drive: ASUS ROG RAIDR Express PCI-E SSD
Graphics cards: 2x ASUS ROG Poseidon Platinum GTX 780 in SLI
PSU: Corsair AX1200i
Other drives: 2x250GB Samsung 840 Evo in RAID0 for Game directory, 1x 3TB Seagate Barracuda for storage.
Now, regarding the CPU... It will not run the memory in XMP; it BSOD's on Desktop. It will boot and sit there at 2133MHz, but fails Prime95 after about 10 minutes. It won't even pass prime95 at 1600MHz, it will only run Prime95 indefinitely at 1333MHz. This is with default BIOS settings, but the VCORE is at 1.3v - seems very high for a CPU that is NOT Overclocked, and is running the memory at such a low speed.
When I first tried 2133MHz, after it failed to run 2400MHz in either XMP, or by manually setting the DRAM frequency, it BSOD as soon as I tried to run Prime95. I went into the BIOS, and configured VCCSA, and VTT LLC to extreme, and current capability to 130%, and also enabled current inrush inertia. This got me 10 minutes of Prime95 before a BSOD. It didn't however, give me any more time in Prime95 at 1600MHz.
The reported voltages for 2133MHz testing are listed below. All voltages were set to Auto, with extreme LLC and 130% current capability on the VTT and VCCSA, and current inrush inertia enabled.
64GB @ 2133MHz Test using Prime95 Blend:
Max core temp: 56°C
This CPU is only 3 days old, and is NOT overclocked. It also seems to be warmer than expected at idle, usually sitting at about 32°C with a 16°C ambient temperature. It is being cooled in a custom Liquid Cooling loop, with an XSPC Raystorm water block. What really concerns me, is 1.3v under load, on a stock multiplier, @ 1333MHz on the DRAM. It is not uncommon for the 4930K, and 4960X to be run with 64GB at at least 2133MHz. A number of the builds I have seen will quite happily hold 2400MHz with a multiplier overclock as well. For some of them, the memory has had to be taken out of XMP, and set to 2133 when the CPU is overclocked, but will quite happily run 2400MHz in XMP without an overclock, and at a reasonable voltage. This is especially true when using a board like mine, the Rampage IV Black edition, yet mine won't even run 1600MHz. I have seen builds to this specification from many different channels, including ASUS Republic of Gamers.
The only conclusion I can come to, is a bad memory controller. The CPU itself is using a very low voltage at idle when running 1333MHz, but under load, it spikes up to 1.3v on the vcore. I have followed all guides from AUS Republic of Gamers regarding the use of high memory frequencies and capacities on this board, and nothing helps. I know that if the CPU can do it, it'll do it on this board, so why won't it even run 1600MHz, let alone 2400?
I have also tested all of the memory modules on my old Maximus V GENE, with an i5 3570K, which had an overclock of 4.4GHz and a vcore of 1.3v. I loaded the motherboard up with 32GB of this 2400MHz corsair Vengeance pro memory, set it to XMP, put the voltage on Auto, and away it went. It passed prime 95 Blend with a vcore of 1.365v. All 8 modules performed the same way. Max core temp was 73°c in Prime95 blend, with an idle temp of about 25-27°c. This 3570K wasn't a great chip; I couldn't get it stable at 4.5GHz with 8GB @ 1333MHz, even at 1.4V with extreme LLC and 140% current capability. However, if it could do 2400MHz, with an overclock of 4.4GHz, my 4930K should be a lot better than it is.