Post subject: Desync issue in the GBC core. Is virtual memory a culprit?
Joined: 9/15/2013
Posts: 154
The GBC version of Dragon Warrior III has insanely frequent desyncs whenever I try to record a movie/replay file. Originally, I attributed it to not accepting input on a frame that contains a save or load state, as this seemed to have helped to avoid desyncs in other games. No dice, though, they're still way too common. "It was also the largest Game Boy Color game released in North America, with 32 Mb ROM and 256Kb of save-state SRAM on one cartridge." Some technical details of the game, likely I assume it's just difficult to emulate properly or something? Those are very, very bloated ROM sizes and SRAM compared to pretty much all GBC games. I have virtual memory 100% disabled as it was causing severe problems/BSoDs when I had it on. But do I need some capacity of virtual memory in order for BizHawk to run properly? I have 6GB RAM and I'm using an i7 so I don't know why it would need virtual memory so fast...
Editor, Emulator Coder
Joined: 8/7/2008
Posts: 1156
None of those details affect the difficulty of emulating it. The size is irrelevant. There could be something else odd about that game, though. Virtual memory probably has nothing to do with this. You shouldn't disable your pagefile, it just breaks things (other than this). If it fixes more things than it breaks for you then I suggest you figure out why it's breaking things. A malfunctioning disk or motherboard/sata device perhaps. It's gonna be bad news eventually one way or another. If virtual memory is in fact involved here, then I would think the only way it could happen in this case is by actual exhaustion of memory which would require the participation of a bunch of other programs sucking down memory. You'd know if that was happening. There's really no reason to suspect this, but I guess it is noteworthily odd that you've got it disabled.
Editor, Emulator Coder, Site Developer
Joined: 5/11/2011
Posts: 1108
Location: Murka
Significant changes were made to GB(C) savestates between 1.6.x and 1.7.x. Have you experienced desyncs on 1.7.1 release?
Post subject: Re: Desync issue in the GBC core. Is virtual memory a culprit?
Joined: 2/3/2013
Posts: 320
Location: Germany
Dyshonest wrote:
[...] I have virtual memory 100% disabled as it was causing severe problems/BSoDs when I had it on. [...]
This should not happen. You should test your hard drives (they almost surely support SMART) and maybe your RAM (with e.g. memtest86) while you're at it.
All syllogisms have three parts, therefore this is not a syllogism.
Post subject: Re: Desync issue in the GBC core. Is virtual memory a culprit?
Warepire
He/Him
Editor
Joined: 3/2/2010
Posts: 2174
Location: A little to the left of nowhere (Sweden)
RGamma wrote:
Dyshonest wrote:
[...] I have virtual memory 100% disabled as it was causing severe problems/BSoDs when I had it on. [...]
This should not happen. You should test your hard drives (they almost surely support SMART) and maybe your RAM (with e.g. memtest86) while you're at it.
SMART tests can lie to you, they are unreliable. Seen many drives pass a SMART test but fail a full read-test horribly.
Post subject: Re: Desync issue in the GBC core. Is virtual memory a culprit?
Joined: 9/15/2013
Posts: 154
natt wrote:
Significant changes were made to GB(C) savestates between 1.6.x and 1.7.x. Have you experienced desyncs on 1.7.1 release?
I have not yet tried 1.7.1. I'll download it and report back.
RGamma wrote:
Dyshonest wrote:
[...] I have virtual memory 100% disabled as it was causing severe problems/BSoDs when I had it on. [...]
This should not happen. You should test your hard drives (they almost surely support SMART) and maybe your RAM (with e.g. memtest86) while you're at it.
Everything checked out fine, even the hard drives which I found peculiar. It was triggering either a serious, interrupting error about my video card, or just a BSoD outright. At one point I saw someone say his variant of the error was solved via disabling virtual memory, and mine was too. For a few months prior I noticed my computer having an unusual over-reliance on it for some reason, anyway. Sometimes I could see an intensive program (if Task Manager tells the truth, anyway), only about 25-30% of my RAM but 100% of my allocated virtual memory (which was set to be 6GB or so). I haven't noticed any other oddities (slowdowns, programs not syncing right, etc) since I disabled it. I guess virtual memory becomes less and less useful the more RAM computers have.
Pokota
He/Him
Joined: 2/5/2014
Posts: 779
Get Process Explorer and re-enable your virtual memory; Process Explorer is better about seeing what process is using what resources. Find that process and determine if you need it, and determine if it's the same process each time. Removing the offending program is much better than removing a safety net.
Adventures in Lua When did I get a vest?
Post subject: Re: Desync issue in the GBC core. Is virtual memory a culprit?
Joined: 2/3/2013
Posts: 320
Location: Germany
Warepire wrote:
RGamma wrote:
Dyshonest wrote:
[...] I have virtual memory 100% disabled as it was causing severe problems/BSoDs when I had it on. [...]
This should not happen. You should test your hard drives (they almost surely support SMART) and maybe your RAM (with e.g. memtest86) while you're at it.
SMART tests can lie to you, they are unreliable. Seen many drives pass a SMART test but fail a full read-test horribly.
Well, there are many types of SMART tests (short and long ones)... It's the only thing I ever used and luckily I haven't had a single HDD die on me so far, so I'm not to judge how reliable SMART really is.
Dyshonest wrote:
At one point I saw someone say his variant of the error was solved via disabling virtual memory, and mine was too. For a few months prior I noticed my computer having an unusual over-reliance on it for some reason, anyway.
Just for terminology: You are not actually disabling "virtual memory", but rather swap space, effectively disabling swapping (referring to the "modern" meaning of paging: http://en.wikipedia.org/wiki/Paging#Terminology).
All syllogisms have three parts, therefore this is not a syllogism.
Joined: 9/15/2013
Posts: 154
Get Process Explorer and re-enable your virtual memory; Process Explorer is better about seeing what process is using what resources. Find that process and determine if you need it, and determine if it's the same process each time. Removing the offending program is much better than removing a safety net.
Most of the time it is Firefox, usually during browser-intensive tasks. I have also seen games consume far more virtual memory than memory, usually the ratio is still 1:3 for memory/virtual memory. It is a fail-safe, but I've yet to see any situations in which it would've helped. To my limited knowledge of virtual memory it was most useful in the days of 95/98 (though IIRC it was only available as a custom, user add-on or something for those) and the early/mid days of XP when computers didn't have as much RAM and processors weren't as powerful.
Just for terminology: You are not actually disabling "virtual memory", but rather swap space, effectively disabling swapping (referring to the "modern" meaning of paging: http://en.wikipedia.org/wiki/Paging#Terminology).
I see, I didn't know that. I thought the Windows menu exclusively referenced virtual memory, but I could be wrong. When I still had it activated I got that Nvidia error constantly, with pretty much anything involving my graphics card. Videos, games, YouTube, etc. Basically made the computer all-but-worthless because the only way things could "run" was by using the integrated graphics card, which is agonizingly slow. The error completely vanished when I disabled the virtual memory/paging. I've yet to try 1.7.1 yet, though. I'll report back later and see if it still causes desyncs. Will my movie files/current savestates be compatible?
adelikat
He/Him
Emulator Coder, Site Developer, Site Owner, Expert player (3598)
Joined: 11/3/2004
Posts: 4738
Location: Tennessee
Dyshonest wrote:
Will my movie files/current savestates be compatible?
Your movie will be "compatible" but will most certainly not sync. Your savestates are absolutely not compatible and could do bad things to your movie.
It's hard to look this good. My TAS projects
Pokota
He/Him
Joined: 2/5/2014
Posts: 779
Hmm... reading that article gave me an idea to bite on. What drive and partition is your swap space (supposed to be) on? How much space does that partition have? How much physical memory do you have? Is any of that added by a video card? Is the physical hard drive that the swap space is assigned to a Solid State Drive or a regular Hard Disk Drive?
Adventures in Lua When did I get a vest?