Picking RAM speed is driving me crazy

[Enten]

So over the past month, I've been reading up on RAM speed differences. Many say there is no noticeable difference in 99% of cases, while others say there is a HUGE difference in certain games and if you're using a Ryzen CPU. I think Fallout 4 was one example of that. 

 

I have a 1700x, paired with an Asus crosshair VI extreme or whatever. I plan to upgrade to Zen2 as soon as those are available. But my motherboard should be able to support whatever RAM I plop into it. 

 

I'm town between this kit, and this kit. The only difference is a speed of 600. So 3000 vs 3600. 

 

Is it worth getting the 3600 RAM for just $25 more? I read somewhere that despite being faster... it's actually slower because of the timings... so confused. 

 

I will be gaming, but primarily will use this PC for 3DS max, rendering, and some Photoshop. I have two Vega 64's if that makes any difference whatsoever. 

 

Thanks!

[mxk]

The difference will barely even be noticeable. 3000 is a great speed for Ryzen so I would save the $25 and stick with 3000mhz.

[Jurrunio]

@nick name the Ryzen user and I think running an aggressive clock (though not as aggressive timings)

 

6 minutes ago, Enten said:

Is it worth getting the 3600 RAM for just $25 more?

I'd say yes just for the greater potential in the sticks... but then it will depend on your manual tunings to get it fast so... ask that yourself.

 

7 minutes ago, Enten said:

it's actually slower because of the timings

Nope, 3600/19 is a larger number than 3000/16, which means the latency on 3600 is a tiny bit lower. Bandwidth is greatly more dependent on frequency than timings so 3600 will guarantee a higher bandwidth as well

 

9 minutes ago, Enten said:

Asus crosshair VI extreme or whatever

This is quite a big thing actually. Crosshair VI is the only board I know to use T-topology while other boards use daisy chain for the memory traces in the PCB (connecting the CPU to the memory). T-top basically means lower potential with 2 sticks, but greater potential with 4 sticks. AMD on Zen 2 seems to have optimized the CPU for daisy chain though, so no idea how well the Crosshair VI will overclock its memory in the future on Zen 2.

[Enten]

1 minute ago, Jurrunio said:

@nick name the Ryzen user and I think running an aggressive clock (though not as aggressive timings)

 

I'd say yes just for the greater potential in the sticks... but then it will depend on your manual tunings to get it fast so... ask that yourself.

 

Nope, 3600/19 is a larger number than 3000/16, which means the latency on 3600 is a tiny bit lower. Bandwidth is greatly more dependent on frequency than timings so 3600 will guarantee a higher bandwidth as well

 

This is quite a big thing actually. Crosshair VI is the only board I know to use T-topology while other boards use daisy chain for the memory traces in the PCB (connecting the CPU to the memory). T-top basically means lower potential with 2 sticks, but greater potential with 4 sticks. AMD on Zen 2 seems to have optimized the CPU for daisy chain though, so no idea how well the Crosshair VI will overclock its memory in the future on Zen 2.

Hmm, guess I got lucky with the motherboard. Only snagged it because it had a $100 rebate. 

 

So in what application would the extra 600 frequency REALLY be noticeable, of not in games or Autodesk products? Think getting the 3600 would be more "future-proof" for Zen 2? I know my current setup, the 1700x can't make full use of the RAM right now regardless. 

 

I've never overclocked RAM, so if it's a bigger hassle than it's worth for a newbie, let me know. I'm willing to tinker but I don't want to permanently damage anything. 

[RobFRaschke]

I'd pay the extra $25. Despite the larger cache and other updates to the memory system on Ryzen 2, the infinity fabric speed is still tied to memory speed and they're going to support 3200 as a default speed, with 3600 being a standard supported speed on Zen 2, with "every kit" they've tested so far just working with the XMP profile.

[Enten]

6 minutes ago, RobFRaschke said:

I'd pay the extra $25. Despite the larger cache and other updates to the memory system on Ryzen 2, the infinity fabric speed is still tied to memory speed and they're going to support 3200 as a default speed, with 3600 being a standard supported speed on Zen 2, with "every kit" they've tested so far just working with the XMP profile.

Okay, going with the 3600! Anything I should know about setting these up to work their best? I ordered 2 kits, so no worrying about which slots to put them in at least. 

[RobFRaschke]

1 minute ago, Enten said:

Okay, going with the 3600! Anything I should know about setting these up to work their best? I ordered 2 kits, so no worrying about which slots to put them in at least. 

Wait, you're using 4 sticks? I didn't see that in the original post. Keep in mind you likely won't see more than 3200 speed, even on Zen2, without manual tweaking with all four slots populated, even if you do in fact have the Crosshair VI, which I hope you do if you're going to run 4 sticks.

[Jurrunio]

9 minutes ago, Enten said:

So in what application would the extra 600 frequency REALLY be noticeable, of not in games or Autodesk products?

Everything, thanks to AMD's (stupid imo) idea of linking uncore frequency to memory frequency. In other words you're overclocking the CPU with memory overclock.

 

10 minutes ago, Enten said:

I've never overclocked RAM, so if it's a bigger hassle than it's worth for a newbie, let me know. I'm willing to tinker but I don't want to permanently damage anything.

Keep your voltages in check and you're fine, though you might want a new Windows installation specifically for testing the overclock, as you'll crash a lot and might corrupt the OS in the process.

 

I'd say the max memory voltage I'd try is 1.5V (maybe 1.45V if you want to ensure lifespan of the CPU), SOC voltage at 1.2V (though higher is not necessarily better), CPU core voltage at 1.4V for 14nm and 12nm Ryzen (dont know how much 7nm Ryzen can tolerate yet)

[Jurrunio]

4 minutes ago, Enten said:

Okay, going with the 3600! Anything I should know about setting these up to work their best? I ordered 2 kits, so no worrying about which slots to put them in at least. 

btw I didnt mean you'll get more speed from 4 sticks compared to 2 just because your board is T-top. It just doesn't tank nearly as hard as daisy chains do when using 4 sticks.

[Enten]

Just now, Jurrunio said:

btw I didnt mean you'll get more speed from 4 sticks compared to 2 just because your board is T-top. It just doesn't tank nearly as hard as daisy chains do when using 4 sticks.

Ah, no worries. Kinda pricey for 2 kits, but I have 13% cashback on ebay and it can't hurt to have more RAM. I always have 200+ tabs open in chrome so...

Can you recommend any easy to follow overclocking guide? There's a LOT of voltage stuff in BIOS... not really sure which to touch and which need to be left alone. 

[Jurrunio]

Just now, Enten said:

Can you recommend any easy to follow overclocking guide? There's a LOT of voltage stuff in BIOS... not really sure which to touch and which need to be left alone. 

@nick name the humanoid guide? He's using a Crosshair VII Hero which should have identical options in the bios

[nick name]

Wait . . . what is going on here?

[Enten]

3 hours ago, nick name said:

Wait . . . what is going on here?

Hahaha. Were you getting tagged all this time?

[xg32]

3 hours ago, nick name said:

Wait . . . what is going on here?

being the only one who actually runs ddr 3600 on zen+ has its burdens.

 

@enten just gonna add that i'd aim for 3600-4000 for zen 2 ram speed, it actually matters quite a bit.

[IDKFA]

3733Mhz CL16 is the sweet spot for Zen2. The further you drift from that point (either in less speed or looser timings) the worse performance gets. 
This speed may increase slightly if you overclock Zen2, And then will depend on how much you over clock it. It could turn out that CL16 4000Mhz is the best. But for stock zen2 is 3733

[nick name]

8 hours ago, Enten said:

Hahaha. Were you getting tagged all this time?

Ok now that I'm sober.  Don't get either kit unless you love the way those Royals look.  The timings on the 3600 are atrocious.  Also, don't buy from eBay Newegg.  They can't price match against Newegg proper.  If you're willing to spend $210 then there are probably better kits.  Your pain is going to come from wanting to run speed on a 32GB capacity kit.  I think the new Ryzen CPUs will handle it a lot better, but I'm not certain your motherboard is going to be as good as the new X570 boards coming out.  

 

If you can afford it then I would suggest 3200MHz b-die.  The Royals are expensive, but this regular TridentZ kit is more reasonable.

 

https://www.newegg.com/g-skill-32gb-288-pin-ddr4-sdram/p/N82E16820232376

[nick name]

This is a test I ran on a 2X16GB kit so it isn't directly comparable, but should be in the ballpark.