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Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

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Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#31

Post by discreteevent »

quantummkv wrote: post #30
javitury wrote: post #26

Earlier quoted context omitted.

> Unless you are building a server, it does not matter The average HN user is not the typical desktop/laptop user. I bet we use virtual machines, compilers, technologies like nvme, databases (postgres/mysql)... more often than the typical desktop/laptop user.

Yes, we do. But I doubt anyone is using them for production workloads. Development workloads don't continuously push cpu to 100% or even 70% for large periods of time. Development workloads don't make 1000 req/sec on postgres. No one has 10 vm's running at a time on a desktop. These perf issues will only affect the server and cloud providers or some edge cases on the desktop. Everyone else can just apply the patches…

You are probably right although C++ compilation can use a fair bit of processor, especially with parallel compilation (e.g. Qt jom). Not sure how frequent system calls are though.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#32

Post by vardump »

vbezhenar wrote: post #18

If you want Intel and can wait, I would wait. They should fix Meltdown bug and it'll increate performance significantly in some edge cases. I think they'll release such processor in 2018. Spectre won't be fixed for a long time, so it should not affect purchase decisions.

2018 sounds a bit early. I'd say we'll be lucky to see engineering samples in 2019, generic availability in 2020.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#33

Post by keldaris »

There's no point in waiting. Neither Intel nor AMD will significantly adjust their roadmaps due to these issues simply because they don't realistically have the flexibility to do so.

Evaluate your threat model in the context of Meltdown/Spectre and opt in or out of the mitigations accordingly. There are relatively few cases where the workload is both significantly affected by the mitigations and vulnerable to these attacks (Xen paravirtualization would be the prototypical example). Personally, I opt out of page table isolation, KASLR and any retpoline-style mitigations on my desktop systems and compute servers for performance reasons. Make sure you understand the implications of these choices if you go that way, though.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#34

Post by kasabali »

discreteevent wrote: post #31
quantummkv wrote: post #30

Earlier quoted context omitted.

Yes, we do. But I doubt anyone is using them for production workloads. Development workloads don't continuously push cpu to 100% or even 70% for large periods of time. Development workloads don't make 1000 req/sec on postgres. No one has 10 vm's running at a time on a desktop. These perf issues will only affect the server and cloud providers or some edge cases on the desktop. Everyone else can just apply the patches…

You are probably right although C++ compilation can use a fair bit of processor, especially with parallel compilation (e.g. Qt jom). Not sure how frequent system calls are though.

C/C++ compilations typically read and write a zillion different tiny files and even if they happen totally in memory buffer they'll still do a hell a lot of system calls.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#36

Post by johnchristopher »

javitury wrote: post #26
quantummkv wrote: post #7

Unless you are building a server, it does not matter. Your GPU handles a lot of desktop heavy workloads such as gaming. If you are building servers or a machine for CPU intensive tasks such as compiling chromium every hour, then you might want to look at AMD. The major performance hits are caused by meltdown patches that do not affect AMD. And the amount of cores they give certainly help in these workloads. Fixing th…

> Unless you are building a server, it does not matter The average HN user is not the typical desktop/laptop user. I bet we use virtual machines, compilers, technologies like nvme, databases (postgres/mysql)... more often than the typical desktop/laptop user.

> The average HN user is not the typical desktop/laptop user.

Maybe so, maybe not. Personnaly I have the hunch that most HN users use the same setup as the typical desktop/laptop users.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#37

Post by kikoreis »

keldaris wrote: post #33

There's no point in waiting. Neither Intel nor AMD will significantly adjust their roadmaps due to these issues simply because they don't realistically have the flexibility to do so. Evaluate your threat model in the context of Meltdown/Spectre and opt in or out of the mitigations accordingly. There are relatively few cases where the workload is both significantly affected by the mitigations and vulnerable to these a…

Do you have actual facts to back up your first paragraph? If it's just an informed opinion, mine is: if you can, you should definitely wait before buying new server parts.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#38

Post by entropie »

javitury wrote: post #26
quantummkv wrote: post #7

Unless you are building a server, it does not matter. Your GPU handles a lot of desktop heavy workloads such as gaming. If you are building servers or a machine for CPU intensive tasks such as compiling chromium every hour, then you might want to look at AMD. The major performance hits are caused by meltdown patches that do not affect AMD. And the amount of cores they give certainly help in these workloads. Fixing th…

> Unless you are building a server, it does not matter The average HN user is not the typical desktop/laptop user. I bet we use virtual machines, compilers, technologies like nvme, databases (postgres/mysql)... more often than the typical desktop/laptop user.

Well, iam not.

Also i do not host critical production machines, but some web and database server. I wonder how the "i host some stuff on the internets" guy is affected by this stuff.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#39

Post by tambre »

sytelus wrote: post #13
quantummkv wrote: post #7

Unless you are building a server, it does not matter. Your GPU handles a lot of desktop heavy workloads such as gaming. If you are building servers or a machine for CPU intensive tasks such as compiling chromium every hour, then you might want to look at AMD. The major performance hits are caused by meltdown patches that do not affect AMD. And the amount of cores they give certainly help in these workloads. Fixing th…

Looks like Intel is already out with a patch for Meltdown: https://www.theverge.com/2018/1/4/16850776/intel-meltdown-sp...

A microcode update, which simply enables some previously disabled features, that allow you to workaround the problem (ie. by clearing the branch prediction buffer). The hardware is still most definitely vulnerable to both Meltdown and Spectre, and will require software workarounds to hide the problems, which in turn will cause lower performance.

Re: Ask HN: Delay buying new devices due to Meltdown/Spectre CPU bug?

#40

Post by usernam »

microtonal wrote: post #17
chrisper wrote: post #14

I just got an 8700k last week. I was thinking about returning it and go with Amd instead. The truth is, I do not do many tasks on my home computer where the CPU is going to be at >50% at all times. The other truth is, that Intel CPUs are just faster than Amd Cpus (now with a few exceptions, but for general use that still applies). I'd say if you are talking about a large quantity purchase, you should maybe wait or lo…

The cynic in me is amazed how people complain about a loss of 0-30% in performance on the desktop (depending on the workload), but are completely happy to replace native applications by Electron applications and/or web applications. Of course, these may be disjoint sets of people. I think when it comes to most desktop workloads, the security issues are far more interesting and serious. And while Meltdown only affects…

As a developer, I'm not so sure about that: I don't use any web and non-native program by choice. In fact, I'm even stricter than that, I can tell you at a distance if a program was written using QML instead of QtWidgets (due to lag and poor behavior) and avoid the first just as I avoid non-native apps.

In fact, unless I'm restricted to a single program I don't have any alternatives to, I'll generally even select programs written in a language I understand and/or prefer.

I have several colleagues that use slightly different metrics, but still pay very close attention to performance and details of the tools they use. Especially if that's something they use for hours over the course of a day.

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