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Re:How “latency numbers everybody should know” decreased fro... by chubot on Thursday March 03, 2022 @05:24PM (#30547868)
What item #3 tells you is that any performance gains in the last decade and a half you've experienced have been driven by multi-core, not faster processors. And that means Amdahl's Law is more important than Moore's Law these days.

Uh or storage and networking? Not sure why you would leave that out, since they're the bottleneck in many programs.

The slowest things are the first things you should optimize

Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Thursday March 03, 2022 @05:45PM (#30548062)
Yeah... SSDs are so much faster than spinning disk it's not even funny.

I literally refuse to run a machine that boots its main OS from spinning disk anymore. The 60 bucks to throw an SSD into it is so incredibly cheap for what you get.

My wife's work gave her a (fairly basic but still fine) thinkpad - except they left the main drive as a fucking 5400rpm hdd. Then acted like assclowns when we repeatedly showed them that the machine is stalling on disk IO, while the rest of the system is doing diddly squat waiting around. I finally got tired of it and we "accidentally" spilled water on it, and somehow just the hdd stopped working (I left out the part where I'd removed it from the laptop first...). Then I just had her expense a new SSD and she no longer hates her work laptop.

Long story short - Storage speeds are incredible compared to what they were when I went to school (when 10k rpm was considered exorbitant)

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Thursday March 03, 2022 @05:52PM (#30548135)
The living room media/gaming machine at home is an 8 terabyte spinning rust. I didn't bother with a separate SSD boot partition.

It's currently been running for 23 days. Booting takes ~15 seconds even on spinning rust for a reasonable linux distro, so I'm not going to stress about those 15 seconds every couple of months.

               total        used        free      shared  buff/cache   available
Mem: 31Gi 4.6Gi 21Gi 158Mi 5.1Gi 25Gi

Swap: 37Gi 617Mi 36Gi

5.1 gigabytes mostly just file cache. As a result, everything opens essentially instantly. For a bit better experience, I did a:

find ~/minecraft/world -type f -exec cat {} > /dev/null \;

to forcibly cache that, but that was all I did.

Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Thursday March 03, 2022 @05:57PM (#30548181)
Hah, if you can fit the whole OS plus running applications easily in RAM, and you don't boot often - fine. But you're basically doing the same thing but with extra steps :P
Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Thursday March 03, 2022 @05:59PM (#30548198)
Well, RAM is significantly faster than even SSD, and now I don't have to muck about w/ a 2nd drive :)

Not to mention the spinning rust is cheaper.

Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Thursday March 03, 2022 @06:08PM (#30548296)
Sure, but that RAM isn't :)

I can get a 60gb ssd for under 20 bucks (I just checked 18.99 on amazon - even I'm a little surprised at how cheap that is)

That 32gb of ram is at least a crisp hundred (which also - fucking mind blowing. First time I ever added a part to a PC, it was to add 256mb of ram, and that was huge deal)

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Thursday March 03, 2022 @06:11PM (#30548330)
Yes, but the RAM is mostly for the gaming. It means I can easily switch between snappy desktop orrr burning a bunch on minecraft worlds and clients or whatever random game is out there. So. A lot more useful than an SSD ;)

Also I'd be concerned about any SSD you can get for that price.

And, frankly, you don't need that much RAM to have a pleasant desktop experience. Most of that is just for the gaming. Just a gig or two of file cache for the hot stuff. Which is what your OS usually does anyway.

The tower my workplace bought me is also spinning rust, and they for some reason put an enormous amount of RAM in it too. Only 5 gigs are actually being used for caching. The OS can't figure out what to do with the rest after having, I suppose loaded browser (few hundred megs), VMWare, OpenOffice etc. Even if I was running something more bloaty than Mate I doubt I could find a way to burn more than another gigabyte :)

Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Thursday March 03, 2022 @06:38PM (#30548603)
I mean... at the risk of asking a loaded question - have you tried an ssd?

Because, I'm also spoiled on RAM so I don't have to pick, but if I haaad to pick - I'd take a machine with 8gb of RAM and an SSD over 32gb of RAM and an HDD almost any day (actually - literally any day except when I'm running our full service stack at work, which needs about 12gb of RAM to be workable)

If I have a bunch of media - sure, throw it on a spinning 2tb drive or something. I'm not saying don't use cheap storage, I'm just saying... try the SSD. It costs about the same as coffee for the week.

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Thursday March 03, 2022 @06:44PM (#30548649)
Yep. All the laptops in the house are SSD. I really haven't noticed much of a difference, sorry.

Everything is linux too, but I find it hard to believe that would matter. I mean, NTFS is a notoriously slow file system (Hedgewars, Firefox and Minecraft all had to rearchitect to handle its horrendous handling of many small files), but the reasons for it I think would not change that much with SSD.

The thing is. How would you really notice a difference after first load of an app? SSD, spinning rust, linux, everything is mem caching these days... It's really hard to tell unless you're actually memory constrained.

It's quite likely that if I had to work on an enormous number of new files, I might notice something? But my software projects aren't like that - the games and videos are, but they wouldn't fit on an SSD anyway. That's why I have an 8 terabyte hard drive.

Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Friday March 04, 2022 @11:13AM (#30556696)
Alright, fair enough - we might just have fairly different workloads.

I absolutely notice a pretty major difference. If you don't - hey, if it's not broken, don't fix it I guess.

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Friday March 04, 2022 @02:05PM (#30558960)
As I think about this, maybe it really is a Windows vs Linux thing. On raw read speeds, SSD is only about 2-3x faster than HDD. This is barely noticeable compared to the speed from RAM, or for almost anything you could reasonably launch. (Videos are huge, but those are basically streamed anyway)

But, random access reads of many small files scattered across the disc, obviously SSD will do much better. Sequential reads (large files, non-fragmented filesystem) it's not so clear.

Maybe it's simply that Linux, as well as being better at file caching and not wasting RAM, is also better at not being fragmented. Perhaps I have my OS filesystems to thank for my indifference.

On that front I guess it's also saving me money by allowing me to enjoy ginormous cheap discs :)

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Friday March 04, 2022 @02:20PM (#30559140)
Hmmm another thought. Linux also (typically and traditionally) does a lot more library reuse thanks to the open source ecosystem. So, there's less DLL hell and fragmentation there. That could be another reason for my not noticing. Most of my system libraries that any random app needs are already loaded and ready for use after boot.
Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Friday March 04, 2022 @04:25PM (#30560802)
Yeah - you might be onto something there - I suspect fragmentation matters a lot for the spinning disks. If you've got huge disks in there, you probably have mostly sequential reads for just about everything.
Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Friday March 04, 2022 @04:22PM (#30560765)
I mean - I also run the ginormous cheap discs. I don't think anyone is saying to load your media library all onto an ssd, it just doesn't matter enough. But the OS/applications are a big deal.

And 2-3x faster is low. For my wife's machine, moving from a 5400rpm spinning disk to a relatively cheap samsung ssd made effective read times about 12x faster. Technically a 5400 rpm drive can do ~75mb/s, but that mostly ignores seek time, and assumes sequential reads. In reality, it was often doing less than 40mb/s. The SSD caps at about 540mb/s, but in reality it mostly does around 450.

It's the difference between having MS teams take ~5 seconds to load, vs more than a minute (locking most of the machine for that period as well).

Re:How “latency numbers everybody should know” decreased fro... by capitainenemo on Friday March 04, 2022 @05:13PM (#30561310)
I just launched Microsoft Teams for Linux on this spinning rust work machine here. It launched a meeting link (letting me into the room) in between 2 and 3 seconds (one-onethousand two-onethousand)

I last launched Teams on this machine a couple of days ago.

For a "fair" comparison (keep in mind, again, the whole point I was making that RAM dominates these days), I then ran:

sync; echo 3 > /proc/sys/vm/drop_caches

And launched Teams again. It opened in between 8-10 seconds with ALL OS caching of disc dropped.

I think what you're seeing here is Windows being helped along by SSD making it usable...

It reminds me of the change we made in Hedgewars. We had no idea it was taking 20-30 seconds to launch our gui in Windows since it opened instantaneously in Linux even with all caches flushed. We had to add lazy page loading to get reasonable performance on Windows - it was probably all about NTFS being insanely slow (and maybe crap at laying out data reasonably).

*Edit - I updated my time estimate upwards slightly for teams after testing the flush several times and my own counting skills.

The flush was also a good test of launching firefox, since I did it once between to update nightly, it also opened very quickly post flush. Barely noticeable delay.

Re:How “latency numbers everybody should know” decreased fro... by zozbot234 on Thursday March 03, 2022 @07:42PM (#30549067)
I agree about this. SSD leads to impressively fast boot/early load times, and it might help if you have to run workloads that stress both RAM and I/O, but other than that it doesn't really matter if you're running a proper OS. And you can put a swap file/partition on a spinning disk without worrying about endurance or having less space for files. So the performance argument goes both ways, and the extra storage space of spinning rust is very convenient.
Re:How “latency numbers everybody should know” decreased fro... by jsjohnst on Friday March 04, 2022 @08:40AM (#30554565)
> First time I ever added a part to a PC, it was to add 256mb of ram, and that was huge deal

I remember the first memory stick I bought (a measly 4mb of RAM) and even wholesale via a friend who worked for a large PC repair shop, it was still $450 give or take.

Now 30 years later, my most recent memory purchase was eight 32gb ECC RDIMMs for about the same price. So not only did the amount of ram per dollar increase 64,000x, it’s also WAY faster and more resilient.

Re:How “latency numbers everybody should know” decreased fro... by andai on Thursday March 03, 2022 @11:45PM (#30550798)
Linux still works OK on spinny disk (though exponentially worse every year as applications trend towards bloated Electron), but Win10 is nigh unusable on a spinny disk (technically works but very unpleasant). It works quite comfortably on ancient hardware though given a SSD and sufficient RAM.
Re:How “latency numbers everybody should know” decreased fro... by wistlo on Thursday March 03, 2022 @06:30PM (#30548524)
You're a good husband. I did the same for my wife, and her 2012 core I7 HP Elitebook acted like it was ten years younger.

But I went a step further: the mother-in-law. She had a lower grade I3 laptop from around 2008 that took 20 minutes to boot Windows 10. It now boots in 15 seconds with a stock 512GB SSD.

I am being rewarded by both (but in very different ways).

Re:How “latency numbers everybody should know” decreased fro... by MonaroVXR on Friday March 04, 2022 @03:09AM (#30551981)
>I am being rewarded by both (but in very different ways).

I'm going to hell for this.

Re:How “latency numbers everybody should know” decreased fro... by girvo on Thursday March 03, 2022 @06:58PM (#30548762)
Lusting after those 10k VelociRaptor drives back in high school... man I have a funny amount of nostalgia for, in hindsight, pretty average hardware once the world moved forward!
Re:How “latency numbers everybody should know” decreased fro... by dekhn on Thursday March 03, 2022 @05:56PM (#30548177)
(your hard drive story is the story of my life, up to about 10 years ago. I have eliminated all but one hard drive from my house and that one doesn't spin most of the time)

Lately my vendor discussions have centered around how much work you can get done with a machine that has half a terabyte of RAM, 96 cores, and 8 NVME SSDs (it's a lot). my college box: 40MB disk, 4MB RAM, 1 66MHz CPU.

Re:How “latency numbers everybody should know” decreased fro... by faeyanpiraat on Thursday March 03, 2022 @06:06PM (#30548280)
I assume you meant half a terabyte of ram
Re:How “latency numbers everybody should know” decreased fro... by jedberg on Thursday March 03, 2022 @06:15PM (#30548387)
My wife was a teacher and we had a similar story. They gave her a perfectly fine MacBook with spinning disk and the smallest memory possible (this was about 10 years ago). I upgraded the RAM to max and the disk to SSD and just put the original pieces away. She was happy, and when it came time to turn it in, we just put the original bits back in.
Re:How “latency numbers everybody should know” decreased fro... by mirker on Thursday March 03, 2022 @06:07PM (#30548295)
That’s fine until you have to store the whole world’s cat videos on Youtube at minimal cost.
Re:How “latency numbers everybody should know” decreased fro... by horsawlarway on Thursday March 03, 2022 @06:41PM (#30548626)
> boots its main OS

Use cheap storage for when you want cheap performance (like those pesky dancing cats :) )