Hearthly wrote:
JohnCoffey wrote:
Don't pair Ryzen with slow ram.
Quick explanation of why.. basically AMD are using something called Infinity Fabric to tie things together. Because of that (and because Ryzen 7 is two quad cores tied together using IF) ram speed makes a massive difference to the IPC. You want 3000mhz ram
No ifs or buts. You will lose 20% performance on 2133 ram. The rather crappy clock speed on Ryzen doesn't help any either.
I guess they're playing it safe because of the early RAM compatibility issues that Ryzen had, but yes they should be offering faster RAM than that by now.
20% might be over-egging the pudding a bit though, a quick Google around a raft on benchmarks shows uplifts from as little as 2-3% up to maybe 15-16%, depending on the application/game.
I agree with the basic point though, faster RAM than 2133MHz should be in a new Ryzen build, might be worth Vision asking what the options are if he decides to order, and indeed why they're only offering 2133MHz in those Ryzen systems.
Games, not so much. As you say, 3-10% max. Cinebench and rendering however?
At 4.6ghz my 5820k (6 core Haswell 12 threads) makes about 1200 points. My 8 core 16t Ivybridge Xeon @ 3.4ghz makes about 1150.
With 2133 ram @ 4ghz a Ryzen 1700 (non X) makes about 1450 points. With 3000mhz ram it does 1700 easy. Same applies to handbrake.. It's mostly when you use all 8 cores. Games do not do so, but The Witcher 3 has been sorted so has Rise Of The Tomb Raider. In those games it does make a difference, all the way up to 3200 when the memory controller becomes flaky and starts to slope off.
But yeah, 4ghz tops is pretty damn lame, so you want to extract every last bit of performance you can. And in real world apps like virtual machines etc it makes a massive difference.
To add. Ryzen works like a dual CPU rig. So there are basically two separate units that are tied together with IF. Dual socket systems suffer from latency between the CPUs. So that's basically what this IF thing is, a way to tie things together and bring down the latency. Threadripper will be even worse, because you now have 4 quad core units. So the faster your ram goes the faster the "bridge" between the two CPUs goes. The latency drops, and the performance really improves. ATM it's limited to like two games and anything that wants all of the cores and threads. But AMD are really working at it, and I think they have a fighting chance this time IMO. Loads of my mates have switched to Ryzen or finally ditched their raging X58 rigs and upgraded to Ryzen.