does RAM speed matter?

[Richard7666]

For both 3ds Max itself and for rendering in V-ray, is there likely to be much difference between ddr3 1600 dual channel and say, ddr4 2800 quad channel?

[chadstevens]

I'm not an expert on the subject, but as far as I'm aware RAM speed has very little to do with most things, it can do some things faster but in the end having more RAM is always better than having faster RAM.

[savage309]

If the RAM die was faster, that would have helped a lot. In fact, the die itself runs on somewhere under 300MHz and that hasn't changed much in the last 20 years (https://raw.githubusercontent.com/sa...emory_freq.jpg)
It is the bus frequency that goes up, this increases the bandwidth, but does not decrease the latency.
There is only one way to know for sure if it will help, and this is to measure. But if I have to bet, I would choose that the ddr4 by itself won't have any significant effect for applications that need a lot of random access (like raytracer).

[Richard7666]

Hmm....so unlikely to justify the price premium?

I mean, I could buy 64gb of ddr3 @ 1600 for the price of 32gb ddr4 2800

[vlado]

Hmm....so unlikely to justify the price premium?

I think it's somewhat unlikely. Even if it did help the render with a couple percent, I think it is way more useful to have the larger amount of RAM.

Best regards,
Vlado

[peterguthrie]

just based on our experience with xeons e5 v2 vs v3 then it does seem that ddr3 vs 4 makes a big difference. especially when you have large scenes that take 30+ gb when rendering.

[Richard7666]

When I made the thread I didn't realise that the Intel x99 chipset was DDR4, so I was forced down that path. Still went with lower clocked RAM though because there is quite a premium on the faster stuff. I guess I could over or under clock it and test if it makes any difference to render times.

just based on our experience with xeons e5 v2 vs v3 then it does seem that ddr3 vs 4 makes a big difference. especially when you have large scenes that take 30+ gb when rendering.

After thinking "that can't be right, a motherboard will only accept one or the other" I found this techreport.com/news/28225/xeon-e7-v3-boasts-haswell-cores-hybrid-memory-controller
Didn't know such hybid beasts existed!

[peterguthrie]

xeon e5 v2 is DDR3, xeon e5 v3 is DDR4 as far as I can remember. I'm mostly talking about the amount of time vray takes to get the scene into memory before it even starts rendering. DDR4 makes a big difference