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Why Cloudflare Chose AMD EPYC for Gen X Servers

blog.cloudflare.com

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Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#91
post #4

Yes, there are lots of stories of individuals and companies choosing AMD over Intel. For me, what's more interesting would be any contrarian view listing the compelling reasons to pay the higher price for Intel instead of AMD. Off the top my head, some reasons would be: - Intel AVX-512 instruction set - Intel 4 and 8 sockets What realistic workloads have a better performance/cost advantage on Intel vs AMD EPYC? If yo…

The rr debugger, which is an amazing productivity enhancer for C/C++ development, still doesn't support AMD: https://github.com/mozilla/rr/issues/2034

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#92

Earlier quoted context omitted.

What "intel-specific integrations"? Cloudflare specifically talks about how they keep their stack runnable across a wide-range of platforms, including even entirely different instruction sets (e.g. ARM). Their own words support my statement. I'm pretty sure it was a "drop-in place" move, and they say absolutely nothing to the contrary. They benchmarked a system that performed better than their existing system for wha…

As I say in another comment... AMD makes sense for us today because of the performance per watt. We continue to keep our software ARM-ready and look at ARM-based solutions. We also continue to look at Intel. We'll use what gives us the best requests per watt. But it is notable that these are our first servers wit NO Intel components at all.

I'm curious why requests per watt is an important metric?

Are you running up against some sort of heat limit or optimizing for electricity cost?

Seems like requests per amortized dollar all in would make more sense. Or requests per cubic foot of data center space if that is your limitation.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#93

Earlier quoted context omitted.

But you are. Facts are facts. Here are some facts: https://www.cpubenchmark.net/singleThread.html AMD CPUs are leading the chart with lower clock rates than Intel's 9900KS (4.0 GHz base, 5.0 GHz boost). Overclock those AMD CPUs and Intel has no advantage.

That isn't games, passmark is a wide splattering of applications, some of which clearly benefit from threading. I have talked about a particular set of circumstances in which Intel wins (and looses) and your source is garbage for that circumstance. https://youtu.be/CGQY9yJqfMs?t=449 Here is another from GamersNexus probably one of the best places for gaming reviews out there https://www.youtube.com/watch?v=yqQ2X1y0jv…

The posted benchmark is single thread performance. So AMD is getting no multi-thread boost.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#94
post #88

Earlier quoted context omitted.

Video encoding comes to mind.

Depends on your use case but the most recent GPU encoders are pretty solid actually. Used to be that they were awful for quality, but more recently they seem to have vastly improved.

The person above was asking what people use AVX512 for and video encoding is a big use case, better GPU encoders don't change that.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#95

Earlier quoted context omitted.

No love for itanium? Aww.

I have never seen anyone have any love for Itanium. It's such a beautiful architecture, but nobody seems to touch it and get out unharmed.

What about it is beautiful? There idea of VLIW?

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#96

Earlier quoted context omitted.

No love for itanium? Aww.

I know this is sarcasm, but: I personally never used Itanium, but the features it had at the time were very compelling. Unfortunately, it was too ambitious, and now it’s faster to do OOO execution instead of making the compiler do all the heavy lifting.

I don't think it every was a promising approach to let the compiler alone do that work. For one, it means that you basically have to recompile for every microarch, and the compiler needs all those details. But even then, the compiler can't fully predict cache behaviour etc. Which means ooo execution still is important.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#97
post #33

Earlier quoted context omitted.

"it shows to me that they are willing to consider bold moves and that they aren’t afraid to be different" Because they benchmarked a drop-in-place commodity replacement as being a better performance-per-dollar for their operation? I'm not sure what's bold about that. I find the notion that they posted a blog entry about this pretty bizarre -- almost rinky-dink. It seems like it's pandering to the AMD fanbase (which I…

There's a ton, just a ton of intel-specific integrations and Cloudflare's switch to AMD was not just a "drop-in-place" move.

intel-specific? I thought AMD was just a drop in replacement for Intel since both same architecture and AMD was a clone of X86 originally, but I guess Intel licensed them the tech so they wouldn't be a monopoloy... but I know that's a bit of a history lesson.

Or did you confuse ARM and AMD? ARM I know you need to recompile your code but possibly other changes depending on what... and I believe there's even compatibility difference between ARM chip versions like 6 and 7, etc. but I guess that's why Apple created bitcode to try to help with that.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#98

Earlier quoted context omitted.

But it's irrelevant if it works faster than intel

It’s not irrelevant if Intel has tools to let you close that gap easily.

Tools can't close a gap of entire cores, much less twice or more of them.

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#99
post #92

Earlier quoted context omitted.

As I say in another comment... AMD makes sense for us today because of the performance per watt. We continue to keep our software ARM-ready and look at ARM-based solutions. We also continue to look at Intel. We'll use what gives us the best requests per watt. But it is notable that these are our first servers wit NO Intel components at all.

I'm curious why requests per watt is an important metric? Are you running up against some sort of heat limit or optimizing for electricity cost? Seems like requests per amortized dollar all in would make more sense. Or requests per cubic foot of data center space if that is your limitation.

This is a good question and I would like to learn the answer too.

According to some napkin calculations, the CPU is $5000 and will be kept in service, I guess, 5 years.

The US average price is 13 cents / kWh so this 225 watts CPU will cost $1280 in electricity over those 5 years.

Colocation price is probably low, let's say $50 / 1U server / month. So that's another $3000.

Why is electricity the most important here? I guess because you can't lower the other 2 costs very much? But isn't the CPU price itself based on the power savings it does provide?

Re: Why Cloudflare Chose AMD EPYC for Gen X Servers

#100

Earlier quoted context omitted.

But it's irrelevant if it works faster than intel

It’s not irrelevant if Intel has tools to let you close that gap easily.

Unless you're doing low-level stuff no developer is going to be aware that this even exists, much less capable enough to use it. There are more 'programmers' than 'engineers'...
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