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FSX OOM at 2.5g mem using W7 64bit

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Hi all,I have FSX running nice finally with an OC 2600k @ 5.0 & W7 64bit with 16g of ram. However I still get the dreaded OOM flying the PMDG MD11, the NGX dose not seem so mem hungry. Using Task Manager and the processes TAB I notice the Memory usage climbs slowly until around 2.5g then I get the OOM.I thought 64bit should allow at least up to 4g. Is there something wrong with my version of W7, it seems like it thinks its a 32bit version.thxdw

Hi all,I have FSX running nice finally with an OC 2600k @ 5.0 & W7 64bit with 16g of ram. However I still get the dreaded OOM flying the PMDG MD11, the NGX dose not seem so mem hungry. Using Task Manager and the processes TAB I notice the Memory usage climbs slowly until around 2.5g then I get the OOM.I thought 64bit should allow at least up to 4g. Is there something wrong with my version of W7, it seems like it thinks its a 32bit version.thxdw
If you don't run SP1 + SP2 or Acceleration, FSX is limited to the usual 32 bit constraints.DJ

He has to have SP2 or Acceleration if he is using the PMDG 737 NGX. Iceman2, Do you have any other software running in the background and have you reported your issue in the PMDG support forum?

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Thanks for the reply, I have not reported this to PMDG yet as I have seen other posts over there on similar topics most with W7 32bit issues.At this stage I didnt think it to be a PMDG problem but more my end. And yes I have Acceleration installed. I guess my question is should I be seeing the mem usage under Task Manager higher say around 3-4.thx

Hi Iceman, what GPU are you using. It's not a GTX580 3Gb by any chance is it?

Howard
MSI Mag B650 Tomahawk MB, Ryzen7-7800X3D CPU@5ghz, Arctic AIO II 360 cooler, Nvidia RTX4090 GPU, 32gb DDR5@6000Mhz, SSD/2Tb+SSD/500Gb+OS, Corsair 1000W PSU, LG Ultragear 48"4K, MFG Crosswinds, TQ6 Throttle, Fulcrum One Yoke
My FlightSim YouTube Channel: https://www.youtube.com/@skyhigh776

  • Author

Hi Rockliffe, I have the GTX590Sorry sargeski I forgot to add in my previous post, I have no other software running just a pure FSX machine.thx

Iceman2,Your GTX 590 is a 3GB video card and more than likely that is the contributing factor to your OOMs. You have to remember that FSX is a 32bit application. Even when running on a 64bit O/S FSX is limited to 4GB Virtual Address Space (VAS). Within that space includes the available video memory. A 3GB card would limit the app itself to 1GB of the 4GB space. Add to this the fact that FSX is just horribly inefficient and sucks down the VAS. Then combine that with huge amounts of mapped video RAM you can see your asking for problems. Many people that have had these issues have replaced there 3GB video cards with cards that contain less RAM and the OOMs cease.Its not a guarantee that your cards the culprit but there is a very good chance it is. If you have access to a 1.5 to 2GB video card you may want to try swapping and see if your OOMs disappear.

Iceman, that is what I thought. As Sargeski has said, a 3Gb card can cause memory issues. This was something that was posted by Ryan on the PMDG forum. It's of no real use as a GPU unless you are going to run multiple monitors. Cheers...

Howard
MSI Mag B650 Tomahawk MB, Ryzen7-7800X3D CPU@5ghz, Arctic AIO II 360 cooler, Nvidia RTX4090 GPU, 32gb DDR5@6000Mhz, SSD/2Tb+SSD/500Gb+OS, Corsair 1000W PSU, LG Ultragear 48"4K, MFG Crosswinds, TQ6 Throttle, Fulcrum One Yoke
My FlightSim YouTube Channel: https://www.youtube.com/@skyhigh776

Actually on a 64 bit OS a 32 bit application like FSX has access to the full 4GB VAS (Minus a few kb's for the system). The video card does not affect the VAS like it would if the OP was running in a 32-bit OS. IMHO the OOM the OP is seeing has little to do with his video card impacting on the VAS. He may have depleted the VAS with complex add-ons or there may not be enough contiguous space for FSX to load into when running these complex add ons. Both of these effects are independent of physical RAM and VRAM.RegardsPeterH

Iceman2,Your GTX 590 is a 3GB video card and more than likely that is the contributing factor to your OOMs. You have to remember that FSX is a 32bit application. Even when running on a 64bit O/S FSX is limited to 4GB Virtual Address Space (VAS). Within that space includes the available video memory. A 3GB card would limit the app itself to 1GB of the 4GB space.
This is incorrect: FSX uses a window of shared memory to communicate with the vide card, so only the VAS of that window is unavailable for use by FSX. Alas, I have no idea what the size of that window is (and nobody else seems to either), and it might very well be that the window is larger for a card with 3 GBy VRAM than one with only 1.5 GBy.Cheers,- jahman.
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Thanks Guys,Very interesting, I have little doubt that you guys are onto it. I read a post somewhere that getting rid of the pagefile so windows is forced to use the main MEM may work (if you have plenty of MEM to spare that is) but it didn't make any difference.BTW I am running 3 screens with the GTX590 and love the quality and clarity with this card, however I do have a few other cards around that are gathering dust that I'll experiment with.So thanks again.Iceman

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Hey Guys I need your help understanding something a little different, Bufferpools.. I've been trying, reading, trying, reading and trying different settings to rid myself of stutters like: Poolsize=0, Poolsize=20000000 and every number in between. But the stutters are worse above the default value of 4m and any number less than 4m developes the blurs. The sweet spot for me is around 3.5m which seems way too low compared with other folks with the same CPU/GPU. My only other tweak I have is the HIGHMEMFIX=1. I dont get it, why so low.BTW so far I haven't had any more OOM's lately after I read somewhere to drop the LOD_RADIUS down a bit when driving the PMDG wagons around. I had it up at 8.5, now its at 6.5.thxIM

Iceman, your LOD could well have been a contributing problem. I also reduced mine from 8.5 to 6.5 because of issues I was experiencing. As for the BufferPools tweak, sure, don't compare it with other guys, as every rig combination is different. I experimented with my last rig over several weeks and came up with a RejectThreshold value of 32750. It was a value I came across purely by trial and error. Some guys on the forum were perplexed with the value, but I can promise you to this day, it gave me an instant increase in both smoothness and performance of about 25%! I would suggest, if you do not already have one, is save a default test flight in your saved flights folder. I have one, guess what, it's marked test flight rolleyes.gif It remains a constant and it's the only flight I turn to when tweaking, otherwise it's a complete waste of time. Find yourself a fairly hungry scenery and aircraft, load onto the end of the runway in VC and then save the flight. Then you can always return to it for test comparisons. Apologies if I'm trying to teach my grandmother how to suck eggs, but sometimes it's the very obvious that is often overlooked. IMHO the BufferPools tweak ie, rejecthrehold/poolsize, are the only tweaks that truly make a big difference.

Howard
MSI Mag B650 Tomahawk MB, Ryzen7-7800X3D CPU@5ghz, Arctic AIO II 360 cooler, Nvidia RTX4090 GPU, 32gb DDR5@6000Mhz, SSD/2Tb+SSD/500Gb+OS, Corsair 1000W PSU, LG Ultragear 48"4K, MFG Crosswinds, TQ6 Throttle, Fulcrum One Yoke
My FlightSim YouTube Channel: https://www.youtube.com/@skyhigh776

Just for the record folks, I have a 3GB GTX580 and I have never had a problem with OOM or any other memory issues. My VAS is the same as anyone elses using a 64bit OS. So any OOM problems are not the video cards memory per se. My first look would be toward any config tweaking as suggested.

John

Rig: Gigabyte B550 AORUS Master Motherboard, AMD Ryzen 7 3800XT CPU, 32GB DDR4 Ram, Gigabyte RTX 2070 Super Graphics,  Samsung Odyssey  wide view display (5120 x 1440 pixels) with VSYNC on.

Just for the record folks, I have a 3GB GTX580 and I have never had a problem with OOM or any other memory issues. My VAS is the same as anyone elses using a 64bit OS. So any OOM problems are not the video cards memory per se. My first look would be toward any config tweaking as suggested.
IIUC in FSX RTM, FSX was saving a copy of its video mem in its address space (I don't think this was the whole memory on the graphics card, just what FSX was using). This was so in a process swap (in XP the video gets deleted until the process gets active again) FSX could restore the video memory. But the OS was saving this as well, so there were two copies being stored, wasting VAS. But in one of the SPs, the FSX copy was removed so that shouldn't be a factor any more. IIUC also, on a 64 bit OS, FSX actually gets a 64 bit address space (upper limit determined by the particular SKU of Win x64 installed). Of course, FSX itself can only "see" the lowest 4 Gb of that, but the OS can see it all and the OS copy of the video mem is in the VAS above 4 Gb. (Also 32 bit apps like FSX do not run directly in 64 bit OS -- they run within a box called windows on windows 64 or WoW64). Also on Win 7 the graphics driver is using WDDM 1.1 which is a different way of managing graphics memory than used in XP.scott s..

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