Does RAM Speed REALLY Matter?? (DDR5 Edition)

How much does RAM speed matter? It's a question we've covered before, but with new platforms from AMD and Intel, and of course the new DDR5 spec, it's time to go down the rabbit hole once more...

Check out the parts on the rigs we used for texting:

And check out some of the RAM we tested:

Purchases made through some store links may provide some compensation to Linus Media Group.

FOLLOW US
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MUSIC CREDIT
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Intro: Laszlo - Supernova

Outro: Approaching Nirvana - Sugar High

CHAPTERS
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0:00 Intro
1:10 Intel
2:10 1% Lows
3:05 Higher Speeds
3:50 Latency
5:15 AMD
6:20 Games
8:10 Productivity
9:00 Conclusion
10:32 Outro

[LinusTechTips]

Are you using DDR5 or DDR4? Heck, maybe you’re still using DDR3! Let us know below!

Check out the parts on the rigs we used for texting:


And check out some of the RAM we tested:


Purchases made through some store links may provide some compensation to Linus Media Group.

[romangervaise]

The fact that a company like Intel are pushing the frequencies just for the Big Numbers without working on better timings gives me that "V8 engine with a bicycle transmission" vibe.

[noxious]

It's worth noting that whilst the 7950X has 64MB of L3 cache vs the 13900K's 36MB, the 13900K actually has a whopping 32MB of faster L2 cache, where the 7950X only has 16MB of L2. The 7950X also has only 1MB of L1 cache, and the 13900K has 2.1MB of L1 cache. It seems that we're seeing something we've seen in the past; more cache means you gain less from fast RAM.

[ActuallyHardcoreOverclocking]

most of the Ryzen 7000 CPU's I've tested can't run 6400 reliably and as such you shouldn't buy anything rated above 6200 for AM5 if you just want to use EXPO/XMP.

EDIT: I should also point out that depending on your luck even DDR5-7200 might be a massive pain to stabilize with intel CPUs. Plenty of CPUs and motherboards will straight up not run DDR5-7600 or higher.

[Reddemon]

If you're watching this in Q3 2023:
-DDR4 prices are about 30% of what's shown at 2:02
-DDR5 7800mhz at 5:12 is ~230 usd vs 370 usd (~60%)

[Ucisneros]

You are always on time with these vidoes/subjects!! Thanks LTT Team!!

[connhughes]

Love the research basis of some of your videos when needed. Looking forward to the future!!

[vexflorez]

I would love to see benchmarks for simulation type games, like Factorio for example. Cause Timings can bring a lot more improvement in those games, than for an FPS that relies mostly on the GPU.

[scraps]

Love to see results from the lab, great work from all the team!

[Nachokinz]

In general, the more an application is bound by the cpu the higher chance that better memory speeds will help; its why AMD's 3d vcache has been well received as more code can be kept closer to the cpu for increased performance.

[NiSE_Rafter]

That was interesting. I have 6000MHz CL36 because it's what was part of a bundle deal when I upgraded to AM5. Didn't think about it much since the CPU improvement was my main goal anyways. GPU bottlenecked for now until the bank account refills.

[MikkoRantalainen]

I'm so glad you included the latency formula around 4:15.

That latency actually tells you what kind of chips the memory has and the timing is basically manufacturing tolerances for the wiring.

DDR5 6000 MT/s CL30 has literally the same memory chips as DDR5 6800 MT/s CL34, just different XMP profile. That's why checking out that CL number is so important while buying RAM.


And the general rule is that if the software (game or app) is written so that the most used data fits in the L1+L2 cache, memory latency doesn't matter and bandwidth is more important. If however, you're running software that needs to access more data than can fit in your CPU cache, higher latency memory will hurt a lot.

As most users have high latency memory because it's cheaper, well optimized games typically run just fine with high latency memory. However, if your favorite game happens to be poorly optimized one, you'll be out of luck with high latency memory.

I'd say go with the cheapest DDR5 RAM that can get you around 12 ns using the formula at 4:15.

[dragonknight]

Considering I NEEDED to use DDR5 on my AM5 build, I'm glad I got it for free as a deal Microcenter runs when you buy both the processor and motherboard there. The GSkill Flare X5 is good running at 6000 speed and for free I can't really complain. Glad to see this being done though, I like to see how much I'm being ripped off for in tech 🤣Nicely done Linus!

[Navidh]

Very nice video on an intersting subject with lots of charts and valueble info but without clear, consise and accurate conclution for average customer!

[djangoryffel]

The whole video took me back a bit to the days when I was still going to benching sessions myself, dabbling in XOC, and my main system was based on a Classified SR2, two X5690 and 2 Mo-Ra 2 radiators, and a 60 liter barrel as an expansion tank. Good old days. Back then I bought and sold quite a few Corsair Dominator GT 2x2 and 3x2 GB kits, always looking for Rev. 7.1A kits. They had the good ICs on them. With water cooling (they didn't like sub-zero temperatures, but also not when they got hotter than 50°C) I could run them at about 2050 MHz and CL6-7-6-20. What a great time, and always selecting out which module is now the bottleneck. Such nice memories. Oh how I miss those days when you could afford PC hardware without having to sell your kidney.

Today all the junk is so expensive and yet none of the sets shown come close to the 5.85ns of my Dominator GT.
I once wanted to sell my whole setup, today I'm glad I didn't, because videos like this show me what sentimental value the system had and still has for me.

[RomanBellicTaxi]

The first Zen CPUs weren't the most stable thing with DDR4 speed. Zen+ did improve that a bit but only on Zen 2 AMD could really push memory overclocking, stability, performance altogether. As Zen 4 is the first DDR5 CPU for them, maybe on Zen 5 we can see 7000+MHz memory working wonders without a hassle and stretch the performance levels.

[ptixs]

I love this type of video, diving a little deeper into how and why ram does what it does. I would love a video (or channel if I may be so bold) that dives really deep into how ram or any tech works. Either way I think the lab will help you guys create videos that scratch that itch for me, looking forward to the upcoming content!

[PurplePhysics]

Well, Im still using my build from 2010 with DDR2. This really helped me pick out what i needed for this next build. Thanks for the help!

[rubencaceiro]

Thank you so so much for this video, was very help full to be able of buy informed

[davidg]

I initially had a CL30 5600 kit in my new 13700k build, but the prices dropped a lot while I was still within the return window so I swapped the RAM for a CL32 6000 kit.
There was a tiny performance increase (calculated latency is almost the same) but a dramatic consistency improvement -- my tests went from 4% variance between results to 1%.
I haven't toyed around with overclocking yet, but will at some point.