Asrock Z77 Extreme4, 3770K, Trident X 8GB 2400 XMP

[zmn668]

Hi. System as follows:

Asrock Z77 Extreme 4 bios 2.80
Intel 3770K overcklocked to 4.6Ghz vcore 1.28
Trident X 2400 2x4gb 10-12-12-31 1.65v vtt 1.13

Need some advice please. Can run this mem at 2200 10-12-12-36 1.65v with everything else on auto and is Prime stable all day long. When I change to XMP will not boot. I saw other advice to increse vtt so I bumped it to 1.13 and it boots and completes a full pass in memtest without errors. Boots into windows, but in Prime 2 workers stop within 20 seconds. Any idea where to go from here? I have custom water cooling of my cpu so I am managing heat although Intel's choice of using damned paste instead of solder for the heatspreader is making my temps higher than they should be and I don't yet have the guts to de-lid it. Thanks!

[emissary42]

Does Prime also crash with memory at 2400 and your cpu at stock?

[zmn668]

Yes. Prime crashes with cpu at stock when mem is set to xmp 2400

[zmn668]

So here is an update...

Flashed to latest bios for z77 Extreme 4 which is P2.90. Slight improvement in that xmp doesn't put it into a boot loop but worker 4 stops within 4 min in prime95 blend. Here are all the settings in case someone has an idea and thanks...

All bios options set for default except Turbo 4.2 overclock chosen. This uses offset voltage and seems to set LLC at level 1. Cpu-z shows avg of 1.248 vcore when in Prime

Mem is set to XMP profile 1 and the board produces the following values:

tcl 10
tRCD 12
tRP 12
tRAS 31
CR 2
tWR 16
tRFC 193
tRRD 7
tWTR 10
tRTP 10
tFAW 26
tCWL 7

Dram voltage 1.665
VTT 1.141
VCCSA 0.925

[zmn668]

Nothing I do can get me past 9 min stable in Prime blend so I guess I will focus on 2200 with tightest timings I can get.

[emissary42]

Your timings and voltages look ok to me and your 3770K should be able to do DDR3-2400 without a hitch. I guess it is the mainboard thats holding you back... Not that ASRock does not know how to get it right (their OC Formula is a beast).

[zmn668]

Yeah. I'm a bit put off. G Skill Ram Configurator lists this Trident X kit when I entered the Extreme 4 MB and I didn't go the next step to look at the QVL list before ordering. I see the QVL does have the Extreme 6, 9 and 11 listed but not the 4. Because of my custom water cooling, I would have to drain the system and replace some of the tubing if I replaced the motherboard so not sure if the jump from 2200 to 2400 is worth all of that. My original Ballistix Sport would max out at 1866 and so 2200 with decent timings should be a nice step up

[emissary42]

Knowing the chips used for your kit, you could probably tighten the timings a bit @ 2200. If you end up with 10-11-11-27 / 9-11-11-27 / 9-11-10-27 / 9-10-10-27 or even 8-10-10-27 the performance difference versus the the higher memory clock decreases quite a bit.

[zmn668]

Got to 2200 10-10-11-31-2N which passes 1 hr of prime. Worker stopped in prime 34 minutes in when I tried 10-10-10-31-2N so seems I might have found my limit. Have to try longer prime run now to see if 10-10-11-31-2N is rock solid. Thanks for your input!

[emissary42]

If you are perfectly stable at 10-10-11-31 2N, the last two things i would try for are lowering the CAS Latency (10->9->8) and reducing Command Rate from 2T to 1T. Both timings have a somewhat decent impact on memory performance. So if you are feeling lucky, just give it a shot.

[zmn668]

Will give it a shot. Thanks!

[zmn668]

I just noticed something if somebody has any insight I would appreciate it. CPU-Z identifies the XMP 2400 profiles with these timings:

Profile 1 10-13-13-32 2t

Profile 2 10-13-13-32 1t

This differs from the xmp 2400 specs that the mem lists as 10-12-12-31. Is CPU-Z known to incorrectly identify the xmp specs?

[emissary42]

Yes, that is a known CPU-Z bug.

[zmn668]

Thanks. Running at 2400 with the settings CPU z shows so while not quite at specs seems better than 2200. Have to do more testing.

[zmn668]

Think I might be on to something. For the hell of it I moved the DIMMS to slots 2 and 4 last night and it boots right up with the XMP settings with my usual 4.6Ghz OC. Ran 10 cycles of IBT on max and it passed. Prime blend made it 49 min before 1 worker stopped but I'm wondering if I have to raise my offset a bit more to account for the increased stress on the IMC. Gonna try that next and I will let you know.