Bufferpools and Texture Bandwidth

[nigyoung]

Hi guys, was reading up on some tweaks for FSX.cfg and came across these two, (Bufferpools and Texture bandwidth).

Was wondering if anyone has had any experience with either of these tweaks that they might care to share?

[solareagle]

Bufferpools can be helpful to reduce stutters when panning around, though it does use texture(video card) memory.  A setting of 10MB is effective in most cases, though you can try a bit higher if you have more than 512MB of video memory.  If going that high induces stutters you might be short on texture memory, so try reducing.  The default value was boosted with SP2 to 4MB, so you can go up from there. 5MB-10MB is good range unless you have a 768MB card.

As to Texture bandwidth multipier, here is what Phil Taylor had to  say:

The mysterious sounding TEXTURE_BANDWITH_MULT is our first target. This is a setting in the [DISPLAY] section of the file, formatted like this:

[DISPLAY] TEXTURE_BANDWIDTH_MULT=n

Where n can range from 10 to some reasonable value that is related to your frame rate limit.

From Rafael Cintron, part of the FS Graphics and Terrain team, comes this description:

“The TEXTURE_BANDWIDTH_MULT option in the Graphics section is the target frame rate use for calculating texture bandwidth. The higher you set this value the more textures we will allocate and copy per frame to the graphics card. The lower you set this value, the less we will allocate and copy up to a minimum limit. As an example, the default rate in the “high†perf bucket setting is 40. The lowest perf bucket setting is 10.

Higher settings on this flag can cause stutters on frames where the terrain system has finished compositing lots of textures. Lower settings can reduce stutters on busy frames and spread out the load across multiple frames“

So thinking this thru, if the value you set is 40, and your frame rate limit is 30, then we will send 40/30 or 4/3 as much textures per frame.

Moving this value to 400, like I have seen some users post in the forums, is probably *not* what you want to do since that increases the texture load on the graphics card by 10x, eg 400/40 = 10x. And after talking about this to Raf, setting it to 0 is ignored and can be validated by setting it to 10 which should give no different results.

[Turnip]

Would a setting of:

[bufferPools]

PoolSize=10000000

Be like setting it to 10MB? Or am I reading this wrong?

[Heiko Glatthorn]

Well, of course it behaves different on each system - but in my case (with a system running on the edge) every value above the default is introducing stutters. That is above default TBM 40 and above default Bufferpool 4000000.

ACES did a great job with balancing those defaults. At least for me...

[Turnip]

I set mine to 20000000. Now I seen to be doing well in rural areas. Next to Sydney airport I get the "close to the airplane" stutters. I think I can live with this. If I am going to use Radar Contact or another program with FSX, I'll set the affinity to 14. Without anything else, I'll set it to 15. That works fine. 

[nigyoung]

Yep I cranked mine up to 12000000 (not as brave as you Turnip) and set the affinity to 14.

It looks like I picked up a few FPS and my textures seem to load quicker. Very smooth in rural areas.

Will keep playing

[Lynchee]

Hi Guys I understand the bufferpools but, ? affininty. Is this the line under [JobShedular].

Lynchie

[Wolter van der Spoel]

[JOBSCHEDULER]

AffinityMask= ..

1  = 1 core           1000

3  = 2 cores         1100

7  = 3 cores         1110

14= 3 cores          0111 mostly used for fsX to leave the 0 core free for other applications

15= 4 cores         1111

cores are 0, 1, 2, and 3 for a Quad core CPU

[Lynchee]

Thanks Walter.

Lynchie 

[Turnip]

nigyoung  Is 12000000 cranked up? I'm not sure. Maybe mine set at 20000000 is way too high.

[solareagle]

Well the default is 4000000, and I used 6000000 my self.  12000000 is high, and 20000000 is very high, perhaps the point where you are wasting texture memory with diminishing returns, though you have to go case by case.

[nigyoung]

Hi Turnip I just increased mine to that figure as an arbitrary start point. Now I'll spend some time flying around to just see if there's any downside. (None as yet). But I think Solareagle is spot on the money, you got to try case by case.

[Turnip]

I'll kick it to 40 and see what happens.

[Maurice_King]

I don't see a buffer pools  allocation in my .CFG  ??  interesting 

[solareagle]

Maurice, you will need to add it at the end of the cfg, otherwise it uses the default 4MB value. 

[bUFFERPOOLS]

Poolsize=n

Its fun to set it really really high as some funny stuff will happen.  For example the wheels of your aircraft may appear above the canopy, the wings will be somewhere else, etc.  Its funny stuff.

[Wolter van der Spoel]

As far as I know the Bufferpool size was initially set to 10000000 and with SP1 lowered to 4000000, setting it to 20000000 is as mentioned a total waste of resources, I've fiddled around with it for a wee bit and for me at 6000000 ~ 8000000 it works fine higher numbers only caused stutters to increase

[solareagle]

Actually it was originally 1MB and upped to 4MB with SP1.

[Turnip]

I just realized that i may have yoo many "0"s in there

[Wolter van der Spoel]

you are right, advice is not to go over 10000000

[solareagle]

4 million(4000000) is 4MB, for example.

[nigyoung]

I just pulled mine back to 8000000 and set my Fiber Frame time Fraction to 0.1 and texture bandwidth to 30

I'm happy with these settings and get a smooth flight although still cop a FPS hiding at YMML. Having said that I can take off and land at 12-15 FPS which is not bad.

My textures now load a lot faster, which I'm very happy about, so no more tweaking for a while.

By the way that's with autogen set at very dense.

I have a spare 500 GB hard drive on my beastie so next step is to re install FSX onto that drive and use that as an FSX dedicated drive.

I have thought of going to vista 64 but we'll wait and see.

[PO]

[JOBSCHEDULER]

AffinityMask= ..

1  = 1 core           1000

3  = 2 cores         1100

7  = 3 cores         1110

14= 3 cores          0111 mostly used for fsX to leave the 0 core free for other applications

15= 4 cores         1111

cores are 0, 1, 2, and 3 for a Quad core CPU

I have my system running pretty good...but this is the only tweak I have'nt performed.

I have a dual core E6850..my AfinityMask should be set to what..1 or 3..?

(I'm asking because the quad core is using 14, pointing to 3 cores leaving 1 for OS, so does that mean I need to set mine to "1" for 1 core leaving 1 core for the OS?)

Thanks,

Po'

[nigyoung]

Set yours to 3. In theory 1 will be for your OS and the other for FSX.

Make the change and do a test flight to see if all is OK. If it is then great, if not then go back to 1 and try that.

The JOBSCHEDULER command has to be entered manually I think unless you've already put it in.

Good luck and let us know how it goes.

[PO]

Thanks, I'll give 'er a try...

BTW..just testing beforehand..

  with no changes yet made...I am monitoring Task Manager with FSX running and it

  is using Core 0 at 100% and Core 1 between 30%-100% already. (seems to be utilizing both cores already without the AfinityMask Tweak).

Any thoughts?

[nigyoung]

Yep, if that's the case then changing the affinity setting will make very little difference.

You could try shutting down all non essential programmes to try and get a boost.

Somewhere on one of these forums was the name of a programme that could be used to accomplish this task. It was called alacritypc I think. Check it out it might be helpful.

What size hard disk do you have?

Nigel