Skylake's IMC Supports Only DDR3L

[Sakkura]

As far as the latencies going up with ddr4, that's to be expected. It's happened with every version of ddr memory so it shouldn't come as a surprise. At a certain point the increased frequencies, even with a slightly higher latency, do perform better. Corsair's xms2 ddr2-800 had timings of 4-4-4-12. With their xms3 ddr3 1600 the timings went up to 9-9-9-24. Cas latency in ddr4 had increased to around 13 for ddr4 2133. Why the tears over the latency of ddr4 and not the tears over the ddr3 latency increase over ddr2?

Upgrading yet fighting to hold onto old hardware that the upgrade is supposed to improve upon just doesn't make sense to me I guess. It's like upgrading a gaming system yet hanging onto the old pcie 2.0 gpu and expecting huge improvements. Why go to the trouble, spend the money etc for the improvements if people are going to negate them. May as well hang onto what they've got. Maybe it's just me but I thought the point of upgrading was replacing the old hardware with newer. If current hardware is satisfactory, no point in upgrading.

The same folks recommending to go skylake instead of haswell/devil's canyon are suggesting a more expensive platform in terms of motherboard, cpu, etc with little gains over devil's canyon but then balking on a few dollars for the newer ram. Pushing for or recommending change while at the same time insisting on stagnation seems to be at odds with one another.

Skylake costs the same as Haswell from Intel; soon enough a Core i5-6600K will cost the same at retail as a Core i5-4690K, and so on. And buying a new kit of RAM can be more than just "a few dollars" - a 16GB kit is in the $100 neighborhood for example.

As for memory latency, bear in mind timings are quoted as a number of clock cycles. And as clocks go up, clocks cycles get shorter. So once you convert the timings to actual latencies in nanoseconds, things don't look nearly as bad. DDR2-800 CL4 has a CAS latency of 10ns. DDR3-1600 CL9 has a CAS latency of 11.25ns. DDR4-2133 CL13 has a CAS latency of 12.20ns. And there are lower latencies available. DDR4-2400 CL14 drops the CAS latency to 11.67ns for example, DDR4-2666 CL15 lands at 11.25ns, DDR4-2800 CL15 hits 10.71ns, and finally at DDR4-3000 CL15 you're back down to 10ns flat. A few of the extreme kits can go even lower, but then you're not just paying a little extra.

 

[rgd1101]

So you are assuming pre-skylake system can handle 1.35V memory without getting bsod.

I'm not assuming it, it's an established fact.

I have an old 775 system that use DDR3, and you saying I can just change the ram voltage to 1.35v without doing anything else?
Just want to be sure where is this fact?

 

[Sakkura]

I have an old 775 system that use DDR3, and you saying I can just change the ram voltage to 1.35v without doing anything else?
Just want to be sure where is this fact?

I don't know if it would be stable on your system. All I'm saying is it's absolutely an option that can be set (any half-decent BIOS/UEFI will have voltage control), and will work in the majority of cases.

Also, you're misrepresenting my statements when you add "without doing anything else." I have explicitly and repeatedly said it will generally require lower memory clocks.