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Performance on netbooks/browsers

Lurks   March 15th, 2010 8:18p.m.

I hauled my tablet to campus today to give skritter a go inbetween lectures. I tested it first at home on Chrome and while it certainly was by no stretch fast on my netbook, it was just about usable.

At uni I use Firefox purely because I have that configured to use the retarded wifi proxy they insist upon. Skritter on Firefox 3.5.5 is unusuably slow on this netbook. I should say it's a current model equipped with an Atom N280 which is one of the fastest CPUs netbooks are equipped with these days.

Has anyone else noticed a performance difference between browsers?

I have to say I don't think this bodes very well for Skritter running on mobile devices when Flash 10.1 comes out. Snapdragon even at 1GHz is a hell of a lot less grunt than the Atom N280.

gacorley   March 15th, 2010 8:22p.m.

Used to have bad performance with Firefox on my desktop, but working equally well with FF or Chrome now (using Ubuntu Karmic Koala).

Byzanti   March 15th, 2010 8:45p.m.

Try the latest Opera (10.5), it's javascript rendering is just as fast as Chrome, but you should be able to configure it to work with the proxy.

Byzanti   March 15th, 2010 8:52p.m.
戴莉絲婷   March 15th, 2010 11:41p.m.

Works fine in Firefox on my Mac. Wonder why not on w/ you?

skritterjohan   March 16th, 2010 4:34a.m.

Note that WIFI may have higher latency. It could make the Skritter app slow as back and forth communication with the server would take longer.

Lurks   March 16th, 2010 8:20a.m.

@gacorley: Interesting, what did you change?

@Byzanti: Using Opera might well be a good bet. I can, of course, configure Chrome to use the proxy but it's a huge pain when I use any other WiFi to switch it back and forth. So it's easier to fire up a browser just for being on campus. Stupid really.

This netbook is an N-equipped unit, so that flash beta doesn't offer anything it doesn't already do. Looks like it's just hardware acceleration for video anyway.

@戴莉絲婷: It's almost certainly a faster machine than a cheap netbook.

@skritterjohan: No, it's not latency - it's the flash app running dog slow. Poor recognition of strokes, jerky animation etc. It's definitely a difference in switching browsers. I actually gave up and plugged my phone into the laptop and used Chrome and it was just about usable.

To be fair, this laptop just isn't fast enough to run skritter. It's not that pleasant to use even in Chrome when it's running properly. The size of the app/web page aint that hot for a shallow height netbook screen either so maybe I'll just suck it down and take my Thinkpad X300 to campus and use that instead. It's no speed demon either but it's definitely a faster CPU.

Actually looking it up, my netbook CPU has a passmark of 316 while the other notebook CPU is 667. Curious given the netbook is a 1.7GHz unit and the faster one is 1.2GHz. I guess Atom pretty much sucks ass :)

葛修远   March 16th, 2010 11:32a.m.

My guess would be it's the wifi. I'm using Firefox on an EEE PC 1000H here, which has an Atom processor. Skritter runs pretty nicely; it's not totally smooth but it's completely usable.

Lurks   March 16th, 2010 5:15p.m.

Ah, that's very good to know! This is an Asus 1005. I'm still not really convinced it's wifi because that wouldn't explain the big difference in performance between browsers but I think I might know what it is.

If this class of device definitely has the horsepower to run Skritter smoothly then I'll go figure out what's wrong with the setup.

Lurks   March 16th, 2010 6:39p.m.

I managed to do stuff to make it run without locking up, so it's usable. I wouldn't really call it fun compared to using it on something that runs it silky smooth - so I think I'm just going to suck it down and take my other laptop to campus.

nick   March 17th, 2010 6:23p.m.

There are big differences in Skritter performance between browsers, with Chrome being much better for some, Firefox for others. The Flash execution in each should be almost the same, actually, but the JavaScript is very different.

Make sure if you're running in Firefox that you don't have another JS-heavy app open (Gmail!), and that you don't have any weird extensions messing with stuff.

You can press Ctrl+Alt+F to see Skritter's framerate and memory usage display for all Flash instances running in a browser. (Corollary: run only one Flash instance in all tabs if performance is an issue.)

You can also try upgrading to Firefox 3.6 or even a dev version.

I've optimized performance a lot already, but there are further (more drastic) optimizations that will be worth doing once they're needed for mobile devices, so we're still looking to make that happen.

If you could share what else you tweaked to improve performance, that would be helpful, too.

Lurks   March 18th, 2010 8:19a.m.

Nick, what I was tracking down was related to lock-ups because of a spectacularly craptastic SSD drive in the netbook, one of the old generation. So small writes are disasterous which is why Firefox tends to do badly on web pages in this environment because it's got a pretty crappy disk cache set up.

Earlier I dismissed the idea of network latency making it look like Skritter was running slowly. I think that was hasty because I took the notebook that runs Skritter very nicely indeed at home (where as the netbook is never silky-smooth) and tried it on campus. The wireless was diabolical so I switched to 3G and ... it was usable but it had the same sort of stuttery pausing stuff going on that I had previously decided was just the flash app performance.

Is it possible that the flash app is blocking because it's waiting for a bit of network data, so following input or drawing a stroke animation gets interrupted?

Not being an expert in this area but I would have thought this kind of thing would be asynchronous so as not to have this effect and maybe it is, but not for 300-500ms worth of latency?

nick   March 18th, 2010 9:00a.m.

Ah, I've read a lot about that SSD problem. I got one of the Intel SSDs with a sane controller in my desktop and it's amazing.

No, the Skritter Flash app is actually very resistant to network slowness after it first loads and gets a buffer. The network driver could be taking up CPU resources if it's really whack, but that seems unlikely.

It sounds as though you have the computers plugged in at home and not on campus. A lot of laptops and netbooks will throttle everything down when not plugged in, including CPU, so that would explain the problems you're seeing. I hope that's it, because otherwise I have no idea.

Lurks   March 19th, 2010 5:43p.m.

Yes exactly, I have one of those Intels in my study desktop. It's amazing, the machine boots faster than my coffee machine will kick out a long black :)

I can rule out CPU throttling, I checked that.

I do have something new though, I tried Firefox on my bad ass desktop PC and to be honest I don't find that silky smooth either. This is 3.6, I tried disabling Mandarin Popup leaving only Google Toolbar enabled but it was the same. The performance graph looked good with a little hitch to 30-odd FPS when the animation glitch comes in. There's seems to be some performance issue on FF of some kind.

Animation issues aren't a showstopper though, it's the input recognition issue where you end up with a straight line because of missing input updates.

I'm utterly rammed with study so I wont have time to get into it right now. However it should be possible to test Skritter on each of the browsers on both laptops via a relatively crappy network connection by using my phone's 3G while at home. More later then.

nick   March 19th, 2010 6:44p.m.

I noticed some jerks related to Firefox 3.6's garbage collection yesterday on my desktop, too. If I looked at total FF memory usage via the task manager, after closing all other tabs but having things open for a while, I could see memory usage jump up by 15-20 megs for a split second, then drop back down a bit lower than before (GC finished). This happened a few times a minute regardless of whether I was moving the mouse or if I even closed Skritter and went to YouTube (although it didn't happen on a simple page with no Flash on it).

So, it may be a Firefox garbage collection issue in 3.6 with Flash? That's all I have so far. When you get a chance, watch the memory usage of the browser when it's jerky and see if there's a similar pattern.

drvelocity   March 22nd, 2010 10:12p.m.

One thing that took me FOREVER to figure out about Firefox - it saves your session every minute or so in case the browser crashes, a great thing since that happens so often for me, but there is a performance hit. I forget the default interval for how often this is set to happen, it may be even less than a minute - but for years I would get annoying little blips while watching youtube videos, or doing anything intensive, despite having a Dual core 2.8ghz computer.

Anyway, this was the culprit for me, perhaps it is for you as well. To change this interval, type about:config in the browser address bar, then search for "browser.sessionstore.interval". I changed the value to 200000, which should be about 3 minutes (that number is microseconds). You can change it to whatever value you see fit.

For the record Firefox crashes so much for me I've been using Chrome pretty much exclusively these past few months..

nick   March 22nd, 2010 10:45p.m.

Hmm, I don't think it's that (probably a good tip though). Mine was set to 10000ms (10 seconds), and these spikes were happening about every 15 seconds (varied a bit, skipped some). I upped it to two minutes and it didn't seem to make a difference.

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