Just How Bad is Mixing Memory?

Summary

在这个视频中，Linus探索了混合使用不同规格内存条的影响，通过在AMD测试平台上进行一系列实验来验证。他们发现，尽管存在通用的误解，但在许多情况下，只要适当调整BIOS设置，不同速度和时序的内存条可以一起正常工作，而且性能损失微乎其微。然而，当尝试将极端不同速度的内存条混合使用时，可能会遇到兼容性问题，尤其是在填满所有内存插槽时。Linus建议，如果可能，购买相同规格的内存条以提高系统稳定性和性能，但也鼓励观众如果有额外的内存条，不妨尝试混用，可能会发现意外的性能提升。视频最后，Linus推广了Micro Center的DIY街机柜套件，强调即使是老式游戏也有其独特的魅力和价值。

Takeaways

• 💾 混合使用不同品牌或规格的内存条在很多情况下可以正常工作，尤其是在调整BIOS设置后。
• 🚀 DDR4内存的兼容性已经大幅提升，使得不同速度的内存条能够更容易地一起工作。
• 🔧 高速内存条通常能够在较低速度下稳定运行，与较慢的内存条一起使用时不会有太大问题。
• 📊 在多种配置下进行的性能测试显示，不同内存组合的性能差异通常在测试变异范围内。
• 🎮 对于游戏和日常使用，混合使用不同速度和时序的内存条对性能的影响微乎其微。
• ⚙️ 在系统BIOS中手动调整内存设置可以帮助提高不同内存条的兼容性和性能。
• 🤔 尽管混合内存条可以工作，但在安装超过两条内存条时可能会遇到更多兼容性问题。
• 🛠️ 选择相同速度和主要时序的升级内存条可以提高兼容性和稳定性。
• 💡 使用来自同一制造商的芯片（不是品牌）的内存条可以进一步提高兼容性。
• 🖥️ 在进行内存升级时，尽管混合不同内存条可能有效，但出售当前内存并购买匹配的内存条通常是更稳妥的选择。

Q & A

混搭内存条是否会对性能造成影响？

基本上没有影响，或者说有时候几乎没有影响。只要你愿意在系统BIOS中调整一些值，使用两根内存条可以适应相当多的情况。

在测试中使用了哪些内存条配置？

测试中使用了五套不同的内存条，这些内存条有不同的速度和延迟，配置在搭载Ryzen 5 3600X和2060 Super的AMD测试平台上。

如果内存子系统不进行超频，DDR4内存的兼容性如何？

如果不进行超频，DDR4内存的兼容性已经有了很大的进步，基本上能够无缝工作。较快的模块通常可以无问题地降频与较慢的模块稳定运行。

混合不同速度的内存条时，性能会有什么变化？

如果你幸运，且你的不匹配内存条能以目标速度运行，那么性能差异不太可能存在。

将2666MHz的内存条与4000MHz的内存条混合会发生什么？

系统甚至可能无法正确开机。当尝试填充超过两个DIMM槽时，问题会进一步恶化，因为更多的模块会增加对CPU集成内存控制器的负载。

AMD Ryzen处理器的flex mode特性是什么？

flex mode允许两个模块以双通道运行，而第三个模块以单通道运行，这有助于在非理想配置中获得最大性能。

内存混搭时，如何提高成功率？

购买速度和主要时序相同的升级内存条会增加成功率，找到使用相同制造商生产的芯片的模块也会有帮助。

是否可以将不同容量但速度相近的内存条配对使用？

可以，这称为异步双通道。只要你的工作负载不超过最小模块的容量，你就不应该注意到任何性能影响。

为什么不推荐随意购买并混搭内存条？

因为每个系统的差异很大，对于你的朋友或我们今天的测试可能有效的配置，对你可能不适用。你可能会遇到重启循环，或者在看似正常工作的设备上遇到不可预测的蓝屏。

如果想要升级内存，应该怎么做？

强烈建议如果你要升级内存，就在Facebook Marketplace或eBay上卖掉当前的模块，购买匹配的替代品。但如果你有备用部件，想看看能否轻松升级而几乎不损失性能，并且不怕一点崩溃时的微调，那么尝试是可行的。

Outlines

00:00

🔧 内存混配的实际影响

视频开始讨论了混合使用不同规格内存的普遍看法，指出这种做法通常被认为不可取。随后，通过在AMD测试平台上使用不同速度和时序的五组内存进行实验，旨在探究混配内存对性能的具体影响。实验结果显示，只要用户愿意在系统BIOS中进行一些调整，使用两根内存条时，混配内存的影响几乎可以忽略。实验还展示了，即使是速度和时序略有不同的内存，只要它们能在目标速度下运行，性能差异也是微乎其微的。但是，当混配极端不同速度的内存时（如2,666 MHz与4,000 MHz），系统可能无法正常启动，表明内存兼容性和性能会受到内存规格差异的影响。视频还强调了填充更多DIMM插槽时可能遇到的问题，包括对CPU集成内存控制器的负载增加，以及可能导致的不稳定性。

05:02

🔄 内存混配的挑战与解决方案

在讨论了填充所有四个DIMM插槽的挑战后，视频指出，尽管有可能找到一个工作的配置，但这种配置的稳定性可能会因不同的BIOS设置和内存条而变化。视频强调，虽然两个不同模块的混配对性能的影响可能微乎其微，但在系统升级时混配内存可能会导致不可预测的结果，尤其是当尝试填满所有插槽时。视频建议，为了提高成功混配内存的几率，购买具有相同速度和主要时序的内存升级，以及尽可能找到使用相同制造商芯片的模块。此外，讨论了不同容量模块的异步双通道运行能力，并指出，只要工作负载不超过最小模块的容量，性能影响应该是可控的。最后，视频建议，尽管混配内存可能在某些情况下工作，但出于稳定性和兼容性的考虑，最好是购买匹配的内存模块。视频还介绍了Micro Center提供的PC硬件和DIY街机柜套件，强调了选择合适组件的重要性。

Keywords

💡内存混搭

指在电脑中同时使用不同品牌、不同时脉或不同容量的内存条。视频讨论了内存混搭对电脑性能和稳定性的影响。内存混搭有时可正常工作,但也可能导致不稳定和难以预测的问题。

💡模块

指内存条。视频测试了混合使用不同速度和时序的内存模块对性能的影响。更高速度的模块通常可以降频正常工作,但也有例外。填满所有内存槽时问题更多。

💡兼容性

不同内存模块之间的兼容性问题是内存混搭的最大隐患。即便参数相近的模块也可能由于控制器、散列等原因出现不兼容现象。兼容性难以预测,每台电脑情况都有所不同。

💡双通道

将两个内存模块组合工作可以双倍内存带宽。视频发现两个不同内存模块混合使用也可以进入双通道模式。但占满四个槽位时,成功进入双通道的可能性很低。

💡故障转圈

由于内存不兼容导致电脑反复重启进入死循环的状态。视频中使用2666和4000内存混合时进入故障转圈。这是内存问题的重要表现。

💡运气

是否能成功使用混合内存在一定程度上取决运气。即便参数相近的混合内存不一定能兼容或表现相近。所以视频不建议太依赖运气去尝试内存混搭。

💡微调

指调整BIOS设置,如手动设置内存速度、时序、电压等参数。适当微调有时可以提高不同内存模块的兼容性,但也可能无效。

💡更新

指更换或增加内存条来扩大内存容量。视频建议更新内存时直接更换成套条相同的内存,不要尝试混合使用。

💡测试

用户可以自己测试不同内存混合使用的效果。但视频警告结果可能不稳定,蓝屏等问题可能随时出现。所以测试需要谨慎。

💡硅片

内存条上实际存储数据的硅制芯片。即使外壳和品牌不同,使用相同硅片的内存兼容性会更好。所以识别硅片也很重要。

Highlights

Exploring the impact of mixing different RAM modules in a gaming PC setup.

Introduction to the experiment using five different memory sets on an AMD test bench.

Baseline performance established with two 8GB modules at 3,200 MHz.

Findings reveal mixing RAM with different speeds and latencies has minimal impact in certain configurations.

Successful tweaking of BIOS values enables compatibility across mixed RAM modules.

Performance consistency observed with modules under 4 GHz when mixed.

Enthusiasts might seek to maximize system performance by increasing memory speed.

A mix of slow and high-speed RAM kits demonstrates the importance of matching speeds for optimal performance.

Challenges in achieving stability and performance with four DIMM slots populated.

The mixed RAM configurations' unpredictability when upgrading or maxing out a system.

Recommendations for improving odds of compatibility with RAM upgrades.

Importance of matching RAM module manufacturer dies for compatibility.

Asynchronous dual-channel support allows for mixing different capacity RAM modules.

Advice against mixing random RAM modules due to potential unpredictability.

Encouragement for personal testing and sharing experiences with mixed RAM configurations.

Promotion of Micro Center for tech and PC hardware needs, including DIY arcade cabinet kits.

Transcripts

(dramatic music)

- Wait a second.

Everyone knows it's bad to mix and match your memory.

But how bad is it?

I mean, if you found a really sweet deal

to double up the RAM and your gaming rig,

would you be such an evil person if you pulled the trigger?

What if the RAM that's in your system

isn't available anymore?

Are you stuck with it forever?

Let's find out.

After we find out just how smoothly Linus here

is gonna segue to his sponsor.

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Use offer code LINUS to get 25% off GlassWire

at the link down below.

(upbeat music)

We never wanna feed you misinformation or myths,

particularly if it causes you to miss out

on a free or cheap upgrade.

So we took five different memory sets from our inventory,

rated for various speeds and latencies,

throw them on an AMD test bench

with a Ryzen 5 3600X and 2060 Super, and went to town,

checking configuration after configuration

after configuration after...

Well, you get the point.

And after many grueling hours of mind-numbing benchmarks,

we're here to give you the exciting results.

Guess what? It barely matters.

Or at least, it sometimes barely matters.

We created a baseline for reference

using two eight gig modules clocked at 3,200 megahertz

with primary timings of 6-18-18-36.

We ran our benchmarks, took notes,

and then started swapping out modules one by one.

And you might be as surprised as we were to find out that,

honestly, for the most part,

with two sticks you can get away with quite a lot

as long as you're willing to tweak some values

here and there in the system BIOS.

If you don't overclock your memory subsystem.

And I'm talking either with XMP or manually,

RAM compatibility with DDR4 has come a long way

to the point where basically it just freakin' works.

Faster modules will generally have no issues clocking down

and running steady with the slower ones,

especially if they're under four gigahertz.

And our performance measurements demonstrate this

with pretty much all of our configurations

within the run-to-run variants of our tests.

But the enthusiasts among you will know

that if you wanna get the most out of a modern system,

increasing your memory speed is really important.

What if we take then half of our reference kit

and half of a slower kit and run them in dual-channel

at the reference kit's frequency of 3,200 megahertz?

Our slow kit here is timed pretty similarly, 16-18-18-35.

But the traditional rule of thumb

is that for every speed bin bump,

you would expect to also raise your CAS latency by one.

I am really not sure if this is gonna work.

Crazily enough, though, the results look pretty good.

Almost as good as our RAM style Tech Scarf on LTTStore.com.

And the benchmarks look identical.

So what we've managed to show here is that if you get lucky

and you're mismatched RAM will run at your target speed,

there's unlikely to be any performance difference.

But remember how I promised we'd find some differences?

What happens if we up the ante,

and mix our 2,666 with our high-speed 4,000 megahertz kit?

Well, the reason DDR4 4,000 costs more than this stuff

is that it's been sorted or binned by the manufacturer

according to their internal performance targets.

Now, sometimes you get lucky

and this puppy'll over overclock to the moon,

but other times, you get our little friend, Mr. 2,666 here.

He managed to be compatible with the big, bad,

extreme gaming modules, but not at their rated speed,

where the system failed to even power on properly.

Things broke down even further

when we tried to populate more than two DIMM slots.

The thing is the more modules you install

the greater the load on your CPU's

integrated memory controller.

This didn't cause any performance issues per se,

as long as we could get the RAM all running,

but it did cause some flaky and undesirable behavior.

For example, when we populated three slots with a mixture

of our reference and slow modules,

the system would post and bench at 3,200 speeds just fine,

at the start, but here's the thing.

AMD's Ryzen processors have a feature called flex mode

that allows two modules to run in dual-channel,

with a third running in single-channel.

That's great for getting maximum performance

out of a non-ideal configuration,

but you've gotta be very careful

how you populate your slots.

As soon as we put our 2666 module in the B1 slot,

it got real unhappy, spitting out memory error codes

and getting stuck in a restart loop

until we reset the CMOS and dialed it all back to 2,666.

As for populating all four DIMM slots

and getting the system to work?

That was no easy feat,

with only a single configuration posting,

and only when we toned it all down to meet

at 3,200 megahertz.

That was below our highest rated modules

3,400 megahertz speed.

Funnily enough, though,

we tried back to this configuration later,

and despite using the same BIOS settings

with the same sticks in the same slots,

it actually failed to post properly during round two.

Which goes to show that while your friend

might have no trouble running a poop mix of memory

with no performance penalty,

you can't count on the same result.

And here's the big problem with that.

Two mixed modules was pretty much fine,

but most people aren't mixing memory

at the time that they buy their brand new system.

It's when they're upgrading down the line

and trying to max out an older system,

that these kinds of questions come up.

So the chance that mixing and matching

will result in unpredictability

when you're maxing out your system and filling all the slots

is just too high to ignore.

Speaking of unpredictable,

get subscribed so you don't miss the next installment

in our crazy Intel home upgrade series.

Andy is doing a man-cave. (clicking tongue)

Back to mixing memory though.

Is there anything that you can do to improve your odds?

Well, yeah, actually.

For starters, buying an upgrade

that is rated for the same speed and primary timings

will help your chances.

And so will finding a module that was built

using dies from the same manufacturer.

And when I say manufacturer, I'm not talking G.Skill

or Corsair or Kingston, I'm talking about the actual chips

that are soldered to the module.

So if you've got a module here with Samsung B-dies,

good for you, by the way, those are nice.

Try to get more of the same,

even if they have a different logo on the heat spreader.

"But, Linus," you might ask,

"what about different capacities?

"Can I pair up similarly specced

"eight gig and 16 gig modules

"and finally join team dual-channel?"

Yes, you can.

It's called asynchronous dual-channel.

So we also ran benchmarks with different capacity modules

of similar speeds and not only did it all register properly

but as long as your workload doesn't exceed the capacity

of the smallest module

you shouldn't notice any performance impact

With that said,

we still cannot in good conscience recommend going out,

buying whatever set of modules is on sale,

rubbing them together for good luck,

and throwing them at your rig.

Both the best and the worst thing about PC gaming

is that every system is wildly different from the next.

To the point where what works for your friend,

or for us today, might not work for you.

You might hit the silicon lottery

and get something that overclocks just fine

and has perfect compatibility,

or you might get something that runs

at exactly its rated speed and not a hertz more!

Worse yet, you might land yourself in a restart loop

or even run into unpredictable blue screens

on a rig that otherwise seems to be working fine.

So we would strongly recommend

if you're upgrading your memory

flip your current modules on Facebook Marketplace

or eBay or something and buy matching replacements.

If however, you've got the spare parts lying around

and you wanna see if you can give yourself an easy upgrade

with minimal or no performance loss,

and you're not afraid of a little bit

of fine-tuning in the event of some crashing,

the good news is that it can work.

So please do some of your own testing

and let us know in the comments below

just how far you were able to push your mismatched hardware.

Who knows, maybe you've had access

to a free upgrade this whole time.

Just like I upgraded my segue to this one from our sponsor,

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If you guys enjoy these kinds of deep dives into memory,

check out our previous look

at the performance impact of ECC memory.

It is slower,

but it might help you keep memory errors at bay.

You can check out findings on that sweet stuff

at the link down below

Or I think we've probably got a thing here. (clicks tongue)