Memory Bus speed change

I'd Google etc but out on phone.

With X99 memory when does the bus speed change? I know that when the RAM starts to get really fast the bus goes to 125.

I will be using a 14 core Broadwell Xeon and from watching a a Linus video last night about an 18 core Haswell I found that with a 125 bus the board failed to post because the Xeon is locked down.

I just don't want to drop money on RAM that won't be able to run at its given speed.

Cheers

 

IIRC When the RAM's XMP profile is higher than 2400 MHz the bus jumps to 125.

 

Ah OK. Absolutely no point in me upgrading from 2133 then.

 

I don't think that's true. I've had 3200 XMP on the 100 strap without issue. It just depends how much you would want to mess with it.

125 BCLK is locked out as it is a dual QPI chip, and Intel have removed that option.

 

Hmm. Well, I guess there is always DSR. Thanks dude.

 

'Ere MDD.. Quick question. So Linus managed a 105 bus on the Haswell Xeon right. The thing that is worrying me is that I have 2133 ram, and I don't think it could handle any sort of overclock. However, the extra 100mhz is very precious with a Xeon, so what would I need to do to bring the ram speed back down?

I'll have a good dig around in the bios but any tips would be greatly appreciated I've overclocked X99 the hard way before but I had Paul helping me PGI is it? something like that, he posts on MLG. Of course it was just far easier to whack up the multi and volts with the 5820k so I've not bothered since.