[Not a bug] Performance problems on a slow machine

Post by **Lunever** » Tue May 16, 2006 10:32 pm

Aw! George has improved so many things for V0.38, also some things I'd been asking for, yet on contrary to V0.37 I virtually can't play it on the machine I spent most time with (pII 297 MHz 256 MB RAM, 60 GB HD, NeoMagic MagicGraph256AV, WinXP Pro, DirectX 9.0c), because it lags seriously. It's still operable, but the lag is serious enough to severely inhibit playing fun.

Since George repeatedly said that most ressources required by RTC are absolutely not used by the dungeon mechanics, but by the graphics display, I wonder, what's so different now compared to V0.37 which worked quite fine with the same config options, and the only thing I really can find on a first glance that's different is the new. calculation of light level. I always used steplighting ON on this machine, and the new steplighting is quite different to the old one (and sorry to say so, quite un-DM and still too quick too bright, but that's a different issue; I do always use steplighting OFF on my other machine BTW).

If my purely speculative assumption should be right, I really really hope that this can be changed back again the way it used to be.

George Gilbert · Post by **George Gilbert** » Tue May 16, 2006 11:28 pm

I very much doubt it's anything at all to do with the light levels. The light level is calculated and updated in a couple of hundred instructions once every 1/6th of a second.

On your machine, executing some 300 million instructions per second, that accounts for about 0.001% of the frame rate...

As you say, nearly all the processor time for RTC is taken up inside the DirectX instructions; I presume they havn't changed and I havn't changed anything in the draw routines that call them between V0.37 and V0.38.

I therefore very strongly suspect that there's something else going on on your machine (unless of course everyone else is seeing similar problems). As discussed on numerous other threads, running WinXP on a 300MHz, 256MB machine is a bit iffy in the first place and I suspect that there's some other process (possibly a WinXP internal thread and so won't show on the task manager) that is slowing the machine down.

Post by **Lunever** » Wed May 17, 2006 2:10 am

Hmm, strange, because there is actually no differenbce in OS or software compared to without the lag, the only thing that has changed is RTC from V0.37 to 38. However, after having played a couple of levels for further testing despite the lag I noticed that it primarily happens when shooting fireballs (config however has always been fireball light off so light shouldn't be an issue and it doesn't seem to be an issue as pointed out by you anyway), and the cloud lag known from 37 is more noticable now. After having adapted and using more poison than fire I got used to the in these conditions slight but still noticeable lag, yet it is strange. When I'll have finished my current test game in a couple of days I will switch back to 37 for testing in order to make sure that it's not some strange windows update side effect or something that isn't related to RTC directly. I will report the result (because the last windows security update is the one and only thing that had been installed recently here - however its already been there when I've been still playing 37 without any lag so it should be virtually .impossible to be related to the lag).

As soon as I can I will compare this behaviour to my other machine (since I do have a desktop in a different place than I am now that has 3 times more speed and memory, but the exactly same configuration in every respect), I'll let you know the result.

Post by **Lunever** » Wed May 17, 2006 12:50 pm

So, by now I did try it on my desktop (AMD 1GHz, 768 MB RAM, 120+20 GB HD, NVIDIA RIVA TNT2 64 Pro, WinXP Pro, DirectX 9.0c), and there are no performance problems at all, even with a couple of other processes running here and more generous config settings like having fireball lighting and transparency on and steplighting off).

I have no clue what's causing the problems on the laptop. Maybe by coincidence 37 was just exactly below the edge that is a tiny bit too much for the laptop, and some minor change in 38 is pushing it just slightly above that edge. I'd welcome any useful ideas though.

George Gilbert · Post by **George Gilbert** » Wed May 17, 2006 1:06 pm

Lunever wrote:I'd welcome any useful ideas though.

You're running WinXP on a <300 MHz box with 256MB RAM - that's less than the minimum recommended spec by Microsoft, and much less than the minimum recommended spec by everyone else!

I'd imagine that's a good place to start

beowuuf · Post by **beowuuf** » Wed May 17, 2006 1:10 pm

Spyware, updates (remember, XP does these behind your back if you tell it to) updates to anti virus etc will all bog your machine down

Post by **Lunever** » Wed May 17, 2006 1:19 pm

I guessed that this would be the first reply. Yet consider:

The machine is 100% free of spyware and other malware. As sure as a user can be.

Updates are all set to manual confirmation, so not updating behind my back.

All processes not integral to Windows are turned off: LAN-connection to the cable modem disconnected, firewall off, antivir off, hell even desktop wallpaper off.

MOST IMPORTANT: Nothing of the above has changed, 37 is running fine without lag, 38 slightly lags, so whatever the cause is, it just has to be found within RTC, not with machine/OS. Of course a more powerful machine or a less big OS would make the problem dissappear, yet despite this I'm dead certain that there's also something in rtc 38 that uses up more ressources than 37, albeit that won't be apparent on most machines of course. Yet since George does not seem to be one of those nowadays wide-spread programmers that go "dah, waste ressources we gotta enough of them" I thought this issue might be of interest.

Post by **Lunever** » Wed May 17, 2006 6:10 pm

I've thought about what's different grafically in 38 from 37 that just tips my old machine over the edge of to-lag-or-not-to-lag, and could only conclude 1 assumption from the following:

1) It is something in 38 because 37 is fine.
2) It has nothing to do with light or dungeon mechanics as pointed out by George, it must be something grafical.
3) Since clouds have always been lagging and now monster clouds in combination with fireballs are lagging most, at least more than monster clouds with poison bolts, it must have to something with spell damage. And the later makes me think:

- Spell damage has been rescaled for 38, esp. on high levels. Is it possible that explosion grafix have thus become bigger and thus take more ressources, which is noticeable only on such an old machine? I'm not sure, but optically it might actually be that they have become bigger (but as I said I'm not sure).

George Gilbert · Post by **George Gilbert** » Wed May 17, 2006 6:48 pm

Nope - Spells all use exactly the same resources regardless of size...

In the config.txt file there's a "FRAMERATE" parameter - can you turn that on then load up a dungeon and wander about doing various things and see what values it gives you (it's written in the top centre of the screen).

Can you let me know what value you get when standing still, moving about, casting spells, fighting monsters etc etc etc. Also does it vary depending on what dungeon your playing (say DM vs the NewObjects dungeon).

Ultimately however I suspect the problem is that you're just running an OS on an machine that just isn't designed to run that OS and its not surprising that your having problems!

Adamo · Post by **Adamo** » Wed May 17, 2006 7:43 pm

GG wrote:

You're running WinXP on a <300 MHz box with 256MB RAM - that's less than the minimum recommended spec by Microsoft, and much less than the minimum recommended spec by everyone else!

my minimal recommendation for XP is 300 Mhz 96 Mb (my machine!

)

Post by **Lunever** » Thu May 18, 2006 2:57 am

As I said: While you might be right that 297 MHz isn't perfect for WinXPpro, and I maybe would have used some other OS if it wasn't that it's actually my gf's laptop rather than my own and she's used to have WinXP on it, 37 does fine here and 38 doesn't, there just has to be some fine difference between the two. Of course I will record framerate. On the other hand, it might be useful for performance testing reasons to have some config option like SPELLRESCALE YES/NO, with YES as default but NO meaning that all spells and especially explosions and clouds will be on a Lo level outlook, no matter the actual power.

George Gilbert · Post by **George Gilbert** » Thu May 18, 2006 10:42 am

Is it *ONLY* when there's an explosion / cloud on screen that the frame rate dips then?

Can you do:

George Gilbert wrote:In the config.txt file there's a "FRAMERATE" parameter - can you turn that on then load up a dungeon and wander about doing various things and see what values it gives you (it's written in the top centre of the screen).

Can you let me know what value you get when standing still, moving about, casting spells, fighting monsters etc etc etc. Also does it vary depending on what dungeon your playing (say DM vs the NewObjects dungeon).

and let me know what you get...

Post by **Lunever** » Thu May 18, 2006 1:56 pm

Ok, I'll test it, but I'll need a couple of days until I'll have time to do so. I'll post the result here.

Post by **Lunever** » Thu May 18, 2006 11:27 pm

For now I only checked the FPS on the old laptop, couldn't compare them to the desktop yet though. I started a new game with a new party to avoid high level settings to have an influence.

Generally the FPS ranges from 1 to 26 FPS. In a rather empty corridor it's 22, walking about makes it 19, combat with thrown missiles or melee usually makes it a 13, poison bolts about 11, fireballs about 9, but clouds drop it to 1-3. If I shoot a fireball at a monster and kill it with that fireball, the FPS very quickly drops to 1, and then gradually returns to its previous usually 19 or so while the monster cloud slowly disappers.

RTC could easily stay compatible to machines even more dumb than that old laptop if the config file had a spelll/cloud-size-rescale switch, and why shouldn't it, after all it also has a switch for portrait rescaling on/off. Rescale off would mean that all monsters would also only produce a small cloud upon death, I'm pretty sure that this would make any performance problems on virtually any old machine go away.
Please include it, it would improve playability a lot for me.

George Gilbert · Post by **George Gilbert** » Fri May 19, 2006 12:52 am

You see, this is what I really don't understand about what you're seeing. The cloud scaling with power was something that was added for V0.35 - if you had suddenly started seeing problems with this then, that would be perfectly understandable.

However, your posts have repeatedly stated that all the way up to and including V0.37 it's been OK and only V0.38 (which has had absolutely no changes to that, or any related or similar, function) is slow...

...it just doesn't make any sense at all.

Post by **Lunever** » Fri May 19, 2006 2:27 am

Yes, in 37 I only got the lag if I cast a couple of poison clouds on the same tile, but not when killing monsters by other means.

Post by **Lunever** » Fri May 19, 2006 2:53 am

It might be something like this:

By conicindence 37 has been using exactly as much ressources as the laptop could handle at normal FPS even with a normal monster cloud displayed.

Some other functionality of 38 takes a tiny bit more ressources than 37, something you'd normally dismiss as irrelevant, because it only takes a minor amount of ressources, yet this minor amount is just the tiny bit too much for the laptop, producing a noticeable lag when the cloud is involved because that's the time when most ressources always have been required, making among all machines just this single computer lag.

Since I wouldn't want you to waste precious time on a problem that is only on 1 certain machine noticeable at all, I think a small-cloud-config-workaround would completely do it, and would probably not be that difficult to implement. At least I'd be absolutely content with it.

George Gilbert · Post by **George Gilbert** » Fri May 19, 2006 11:58 am

Lunever wrote:RTC could easily stay compatible to machines even more dumb than that old laptop if the config file had a spelll/cloud-size-rescale switch, and why shouldn't it, after all it also has a switch for portrait rescaling on/off. Rescale off would mean that all monsters would also only produce a small cloud upon death, I'm pretty sure that this would make any performance problems on virtually any old machine go away.
Please include it, it would improve playability a lot for me.

Seems reasonable - and now done for V0.39.

Actually, I've been able to do better than that and have some rough indication of power even with the scaling turned off (for example for Lo power by displaying the pre-rendered "far away" frame when close up) with minimal impact on the frame rate.

Post by **Lunever** » Fri May 19, 2006 5:51 pm

Thank you, George!

Post by **Lunever** » Sun May 21, 2006 6:07 pm

For comparison: On the desktop specified the game runs at 22 - 39 FPS even with the usual wallpaper, antivir, firewall, ISDN-monitor, DSL-connection and IE-Encyclopaedia still active, and with everything useful active in the config. Killing a single monster will drop it to 12, but only for a short moment, killing a group of monsters simulataneously will drop it also to 3 FPS, but again only for a very short moment, so it isn't as noticeable as on the laptop specified.

mikko · Post by **mikko** » Sun May 21, 2006 8:38 pm

From 22 to 3 when killing a group of monsters? So the death animation for them would increase CPU load at least by a factor of 7.

That kind of a drop to me sounds more than a bit too much..

beowuuf · Post by **beowuuf** » Sun May 21, 2006 8:42 pm

That would be a cloud, just like the poison cloud lag

George Gilbert · Post by **George Gilbert** » Sun May 21, 2006 8:55 pm

Yep - they're all clouds and it's all the same issue (although again, it only changed in V0.35, so I've no idea why it's only a problem in V0.38).

Des · Post by **Des** » Sun May 21, 2006 10:52 pm

During really hectic battles playing on the ST back in the 80s the game would slow down quite markedly, giving you extra time to gulp a few VI potions. Playing RTC using an Athlon 64 X2 processor no such luck. 59 FPS all the time. Perhaps if I install Windows Vista...

Post by **Lunever** » Tue Jun 13, 2006 1:50 am

BTW: The new config option did solve this problem on my machines.

Daecon · Post by **Daecon** » Tue Jun 13, 2006 2:21 am

Slightly off topic, but will RTC work on an Apple Mac laptop computer?