New CPU and Motherboard, same RAM, better memory OC

[scuzzycard]

I am on my fourth Asus X99-A and my third Intel 5820K. I've been using same 32GB kit of Crucial Ballistix Sport on each build.

This memory was great at 2400MHz on every board, with 11-11-11-27 CR1 at 1.35V, but 2666 was not stable at any setting ever. With this new board and chip, all that's changed - it's running rock stable at 2666MHz 12-12-12-30 CR1 1.35V. 2800 didn't boot at 14-14-14-32, but I haven't really played with it enough to say that it wouldn't be possible with a higher system agent voltage (currently at 0.95V).

Why did this happen exactly? Better IMC in the CPU? Newer BIOS that came with the newer board? I did not think there was that much variance with the same exact model CPU and motherboard, but I guess I learned something new today.

 

[rhysiam]

It could be a newer BIOS revision as well. Not sure...

I realise I'm not answering your question, but curiosity has me needing to ask: why 4 mobos and 3 CPUs? What happened??!

 

[scuzzycard]

To make a long story very short:
1st board and CPU: Prime 95 and 4.5GHz/1.325V
2nd board: PCI-E slot failed after 1 month.
3rd board and 2nd CPU: Intel Burn Test and 4.5GHz/1.275V

Apparently the 8-Phase power delivery is not enough when running Prime or IBT and overclocking. The motherboard fails and takes the CPU with it.

 

[rhysiam]

To make a long story very short:
1st board and CPU: Prime 95 and 4.5GHz/1.325V
2nd board: PCI-E slot failed after 1 month.
3rd board and 2nd CPU: Intel Burn Test and 4.5GHz/1.275V

Apparently the 8-Phase power delivery is not enough when running Prime or IBT and overclocking. The motherboard fails and takes the CPU with it.

Wow! It's not even like your voltages were all that high? Anyway, hope someone can shed a bit more light on your question.

 

[scuzzycard]

I agree - Asus should have made these boards more robust. People buy them to overclock, and people who overclock have been running Prime 95 for nearly 2 decades. I've gotten used to the idea of keeping it under ~200 watts at all times now that I understand the problem. Thats means no Prime, no IBT, and no AIDA64 FPU test when overclocking (and I'm always overclocking).

But I'm happy now. This new CPU is best overclocker I've had yet. I have it at a very conservative 4.6/1.225V. Maybe one day I'll give this board to my son, and see just how high this chip can really go in a 12-phase motherboard.