I know a lot of people feel that 8 GB of RAM is sufficient for running FSX optimally. But has anyone actually done controlled tests directly comparing 8 GB versus 12 GB or 16 GB or more, with all other variables being equal?

FSX is a 32bit application. There is NO benefit from having more than 4GB of free RAM (Not counting that used by the OS or anything else you have running).

Yep. I agree with the above post, however, having 8 GB of ram is usually good. 4, you might be finding yourself sometimes with the NGX and a lot of addons having trouble.

 

I have 32GB of RAM, but I only have so much because I am running other programs.

 

I used to have 8 GB , and I saw no difference between 8GB and 32GB.

I know when I went from 8gb of DDR3 1600 to 16gb of DDR3 2133 and ran FSX mark the gain was no more than 2fps.

You could use some of that free memory for a RAM disk, which could be configured to usefully speed up FSX, maybe.

In fact shouldn't Windows be automatically using free space as a disk cache?

Cheers

Keith

Yep. I agree with the above post, however, having 8 GB of ram is usually good. 4, you might be finding yourself sometimes with the NGX and a lot of addons having trouble.

 

I have 32GB of RAM, but I only have so much because I am running other programs.

 

I used to have 8 GB , and I saw no difference between 8GB and 32GB.

 

When you say you saw no difference going from 8 GB to 32 GB, do you mean that you saw no difference in running FSX alone or that you saw no difference in running FSX along with your other programs? (And by other programs, do you mean FSX-related stuff or completely unrelated stuff like mp3 or video players?)

Yep. I agree with the above post, however, having 8 GB of ram is usually good. 4, you might be finding yourself sometimes with the NGX and a lot of addons having trouble.

 

I have 32GB of RAM, but I only have so much because I am running other programs.

 

I used to have 8 GB , and I saw no difference between 8GB and 32GB.

 

Just to be clear, I meant 4GB free, e.g. with ActiveSky, Vatsim, and whatever else you have already running.

When you say you saw no difference going from 8 GB to 32 GB, do you mean that you saw no difference in running FSX alone or that you saw no difference in running FSX along with your other programs? (And by other programs, do you mean FSX-related stuff or completely unrelated stuff like mp3 or video players?)

 

FSX Alone.

You could use some of that free memory for a RAM disk, which could be configured to usefully speed up FSX, maybe.

In fact shouldn't Windows be automatically using free space as a disk cache?

Cheers

Keith

 

Yup, its called SuperFetch. I find it a very helpful feature. My 8Gigs are used up all the time because of it.

I know when I went from 8gb of DDR3 1600 to 16gb of DDR3 2133 and ran FSX mark the gain was no more than 2fps.

 

In this case the gain would have been from going 1600Mhz to the faster 2133Mhz Ram, not from going 8Gb to 16Gb.

Yup, its called SuperFetch. I find it a very helpful feature. My 8Gigs are used up all the time because of it.

 

This. And besides superfetch, windows does also cache disk, of course. You may see say 5GB of RAM in use at a certain point, but the remaining memory could be populated with cached stuff.

FSX is a 32bit application. There is NO benefit from having more than 4GB of free RAM (Not counting that used by the OS or anything else you have running).

 

A study by Tomshardware confirmed that this is generally true. Testing for benefits of additional RAM with 32-bit applications but without a RAMdisk, confirmed that 6GB or 12GB provided no benefit for single-task applications over 3GB.

http://www.tomshardw...ade,2264-6.html

 

BUT there's that caveat of "not counting that used by the OS or anything else you have running," which it turns out may be crucial (as with the reference to SuperFetch):

 

You could use some of that free memory for a RAM disk, which could be configured to usefully speed up FSX, maybe.

In fact shouldn't Windows be automatically using free space as a disk cache?

Cheers

Keith

 

Ah, this is a great idea!

Tomshardware looked into this a couple of years ago (not for FSX, of course, unfortunately but for other 32-bit applications), and found that there WERE definite improvements (eyeballing it, it looks like about 10-15%) going from 8GB to 12GB if the additional RAM was used as a RAMdisk for swap/temp files. (Interestingly, going from 12GB to 16GB did not make a difference.) Take a look at their charts:

http://www.tomshardw...ade,2778-5.html

 

They also made the point that in some cases although 32-bit applications might not show improved FPS when running with more memory on 64-bit hardware, there might be other, visual improvements that are much harder to quantify. They found, for example, that even though FPS were virtually unchanged in Grand Theft Auto IV from 6GB to 16GB, there were fewer visual artifacts at the higher RAM levels.

 

-- So this has me intrigued. I wonder whether some FSXers have been able to get benefits from more than 8GB with RAMdisking.

 

--The other question, is how does having an SSD factor into all this? Accessing a RAMdisk is faster for the system than accessing an SSD, but is it so much faster that it makes a difference that you would actual notice while playing?

 

--Yet another question this raises is how does the increase in RAM above 8GB factor into overclocking?

More RAM modules and higher RAM sectors mean more work for the memory controller, so more heat and voltage. Would it mean so much more that there would be a negative impact on how much you would otherwise be able to overclock the system, so that, on balance, there would be no net benefit (and possibly even a detriment) for those who overclock?

RAM disk is snake oil when running under an OS with proper memory management, like Win 7. RAM is volatile and data on disks is supposed to be persistent.

Since the OS already caches data, as the RAMdisk is loaded (be it upon bootup if made persistent or as you access the data for the first time if made volatile) you're going to have it duplicated in memory, and then you'll be accessing regular RAM anyway.

Of course with a persistent RAMdisk you may see an increase in performance the first time you run something, since it preemptively loads stuff in RAM, but those tests don't account for the boot time penalty that comes with it, and the potential penalty from having data twice in memory, which is obviously a waste of resources and could potentially get something else evicted from memory that you may need in the near future. Superfetch does that preemptive memory load a lot better, or you can just go with SSD's and move on.

 

So in short, RAM is RAM and disks are disks. Nothing will change the fact that RAM is not persistent, so if you need your data in memory, let the OS cache it and if you want it loaded preemptively, let Superfetch do it's thing.

With 4gb on XP I got ocasional OOM errors with FSX. With Win 7 and 8gb I have never had an OOM. I have FSX installed also on one of my DAW machines with 64gb and it makes absolutely no difference over my dedicated FSX machine running 8bg. Also not really to do with ram, but I just bought a Hailea water chiller and successfully clocked my CPU to 5.5ghz, and see no noticeable improvement over the 5.0ghz I had on high end air. So there seems to be a point of diminishing returns with FSX and pushing for ever higher hardware specs. The biggest improvement I've seen over this past year has been with SSD drives, scenery no longer pops in and textures load instantly. sorry for ranting a bit off topic.

 

Chris

With 4gb on XP I got ocasional OOM errors with FSX. With Win 7 and 8gb I have never had an OOM. I have FSX installed also on one of my DAW machines with 64gb and it makes absolutely no difference over my dedicated FSX machine running 8bg. Also not really to do with ram, but I just bought a Hailea water chiller and successfully clocked my CPU to 5.5ghz, and see no noticeable improvement over the 5.0ghz I had on high end air. So there seems to be a point of diminishing returns with FSX and pushing for ever higher hardware specs. The biggest improvement I've seen over this past year has been with SSD drives, scenery no longer pops in and textures load instantly. sorry for ranting a bit off topic.

 

Chris

 

Chris, how loud is that Hailea? And what parts have you included in your water cooling setup, if I may ask?