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Does FSX benefit much from more than 2GB?

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I see the 3GB switch can be used, which is apparently built into acceleration, so I am wondering if anybody has before and after experience with using more than 2GB? I will be putting together an E6850 system soon, and I don't want to drop the extra cash on memory unless there is a noticeable difference. Thanks

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Possibly you or the moderator could drop this question over in the Hardware Forum for a response... I would also like to know. I have 4 Gigs. I know that Vista only recognizes about 2.85 max, or something like that. I am not computer "smart" so I don't know if there is anything that can be done to take advantage of more. But I certainly would like to know.Steve

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A 32-bit system can only address 4Gb of physical mmemory. Allocating 3Gb to an application leaves 1Gb for everything else - including the operating system etc.I understand that that this may not be enough for high-performance video cards that may require a csignificant amount of physical memory.

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The way I understand it is the video card memory is part of the 4GB total.If you have 3 GB RAM and a 756MB video card - you have 3.756 GB of memory for the OS to use for all purposes.If you ahve 4 GB RAM and a 756MB video card - you have 4 GB of memory for the OS to use for all purposes.

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Doesn't that support my point?If you have 4Gb of RAM and use 756Mb for a video card and allocate 3Gb to an application then surely the operating system would only have 244Mb available for its own use? This could be inadequate.

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I believe the northbridge masks much of the physical address space in the region of about 3.3 - 4.0 Gig. On a 64 bit OS any physical RAM at that address can be remapped above 4G, but in 32 bit OS the memory can't be remapped and so isn't visible. (I think there may be some methods in which 64 bit drivers can get around that.)Separately, each app gets 4Gb of virtual address space, and I believe it is in this space that the video memory gets mapped so the application can't use it for it's own storage, even if it is large address space aware (able to use virtual address above 2Gb).scott s..

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If you go to vista 64bit it will recognized all your ram and is a much faster operating system. I have 4gigs of high end ram and I'm getting high fps with the sliders moved pretty much to the left. I keep AI traffic lower because I don't want to do a lot of go arounds.Make sure you use the vista patch before any 3rd party add-ons or you will get a memory error.Capt.Mac

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I wish I could provide the answer to your question as all the other responses are not addressing it, with the exception of Capn Mac.I can tell you this: I have measured the amount of system and video memory used on my XP install of FSX and have not reached 100% of 1 Gb and 320 Mb, respectively. It has been very, very close to 100% though. I'm confident higher slider settings and higher res textures would more than max out my system.

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The problem I had with going over the 2Gig was...I had to throttle down my over clock that I had done.I have my dual Core running at 3.5Ghz. and when I increased from 2Gig to 4Gigs.. It didn;t like my OC.So the question then was... do I have my 4 Gig running at 2.4Ghz or do should I just go with 2Gig memory and the system running at 3.5Ghz.I chose the 2Gig + 3.5Ghz and returned the 2 Gig memory.I am really curious to know from Over clockers where they have 4Gig memory + their over clock intact!Manny

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>>I am really curious to know from Over clockers where they have>4Gig memory + their over clock intact!>>>MannyThey might be using 2 sticks, whereas you were probably using 4 sticks when you tried your overclock. Just a guess...RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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Yes.. I was using 4 sticks.Are you saying,.. If I had used 2G X 2 I may have been ok?Manny

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Hi Manny,I'm using 4 1 gig sticks under Vista Home Premium... and it didn't seem to affect my overclock. I added two sticks after I was running the E6700 at 3.6 gigs. I still haven't concluded from this thread whether or not (at least the 4th stick) is doing any good). Take care,Steve

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4 sticks should be ok, but of course your OC will be limited by the weakest memory chip on any of the 4 sticks.

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I suppose somebody with 4GB would have to benchmark, pull out 2GB, and then benchmark again.

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Just couple of days ago, I bought myself same 2 Corsair sticks, same which I have built in, to go from 2GB to 4GB, just to see if there will be any performance increase...Absolutely none, big problems with some programs (non-FS), my scanner driver had a problem with it too, I tested /3GB and /PAE switches, Memory Remap on my P5B Deluxe to be able to address more, nothing really seemed to work, Remap brought only 2GB visible in 32bit Win, XP64 is utter crap, Firefox wasn't even working properly, programs crashing, system unstable.And also, performance increase was close to none with 2,93GB visible without Memory Remap and without 3GB and PAE switches.And as XP doesn't cache applications and Vista does (or so I heard), there was no way for me to use the additional RAM.So I brought it back.

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I've used FSX with 1, 2 and 3GB memory at various times on Windows XP. Although I didn't run the same FSX benchmark on each, subjectively I can report:1GB - FSX very slow to load up and much ongoing hard drive usage, and hence stuttering, while flying. Windows task manager reported that all physical memory was in use. Had to reduce scenery settings to get the game usable. And this was before starting up addons!2GB - FSX loads up reasonably fast the first time, and very quickly if restarted straight after exiting FSX due to memory caching effect. Settings can be maxed without exhausting available memory, EXCEPT at OOM holes like ZBAA where nothing but the lowest settings will stop FSX bombing out. Addons work fine, again without exhausting memory. Definitely the sweetspot RAM amount for FSX.3GB - Similar results to using 2GB, except the caching effect is much more pronounced ie. you can start and shut down other apps, then reload FSX later and it is still cached. Also, there is a lot of free physical memory left after loading up FSX + addons, often around 1.2GB free. OOMs can still occur, even with such free physical memory, without using any 3GB aware settings. I did briefly try the /3GB switch and the >2GB aware hack for FSX.exe, but that caused my whole system to become unstable and crash-prone, so I undid those changes.Re # of memory sticks affecting performance, I found on my system that any combination of two sticks allow me to OC to 3.5GHz, but 3 or 4 sticks lower my stable OC to 3.2GHz.Re 4GB, XP and Vista 32 bit won't see this anyway, so for those OSs it is a waste. With XP and Vista 64, obviously it will be seen but IMO the benefits would be minor because 3GB already gives a nice memory caching capability. The >2GB aware change in FSX XP2 will likely reduce OOM occurrences on both 32 and 64 bit OSs, however instability may still affect 32 bit OSs as I experienced.Gary

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Hi,FSX will benefit only I high settings and places where lot of memory needed.To make full use of 4 GB you need a 64 Bit OS, like Windows XP 64 or Windows Vista 64.If you try too overclock the additional two RAMs can lower your oc results. A successfull oc is harder too get, because sometimes the system crahed only if it use the whole ram. You should use Prime95 (?) to test, it can use all ram.If your system is stable, FSX will normal use up to 2 GB of Ram leave the rest for OS and caching. Esp the Ram for caching will make the flight smoother. Also the Ram for the OS will reduce swapping.Another benefit is, that programs like ASX will use the Ram too.I did not run any benchmarks, but it should be a smoother ride with more Ram.Maybe with the SP2 patch FSX will use more than 2 GB. If they compiled the binaries with the /3GB it could help more than the normal hack.But again, more than 2 GB is only a good option if you go to 64 Bit OS.Just my 2 cents.

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not a lot ...I have Vista 64 + 4 gig RAMI've never seen the memory usage go above 800MB ...:(

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>If you try too overclock the additional two RAMs can lower>your oc results. A successfull oc is harder too get, because>sometimes the system crahed only if it use the whole ram. You>should use Prime95 (?) to test, it can use all ram.>If your system is stable, FSX will normal use up to 2 GB of>Ram leave the rest for OS and caching. Esp the Ram for caching>will make the flight smoother. Also the Ram for the OS will>reduce swapping.>Another benefit is, that programs like ASX will use the Ram>too.Markus, I am using Vista 32. Do you mean that 4 Gigs is a GOOD idea, BUT it will lower overclocking results? Are you speaking of CPU overclocking OR RAM overclocking?Thanks,Steve

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Is there any complications in running 32-bit applications (or even 16-bit) in 64-bit Windows XP or Vista?

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Hi Steve,no I dont think that Vista 32 and 4 GByte is a good combination. I have this before and the results are not great. I switched to Vista 64 and the results are much better now.So no recommendation of Vista 32 Bit with more than 3 GByte.The OC results of memory and of the CPU could be lower with more than two memory modules. My OC hardware dealer said he could not guarantee that the system will OC. I bought a pretested Core Duo (Stock 2.4 GHz pretested Overclocked too 3.42 GHz) I added good RAM on my own and still can go for 3.42 GHz. The Ram is DDR2 400 MHz and runs at 380 MHz so no OC on this side.If you try too overclock Ram and processor I guess it will be even harder to get success.>>Markus, >>I am using Vista 32. Do you mean that 4 Gigs is a GOOD idea,>BUT it will lower overclocking results? >>Are you speaking of CPU overclocking OR RAM overclocking?>>Thanks,>Steve

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>Is there any complications in running 32-bit applications (or>even 16-bit) in 64-bit Windows XP or Vista?Hi,64 Bit Operating systems will not run any 16-Bit application! (see here http://support.microsoft.com/kb/896456/en-us)So if you still have 16-Bit Applications you must use a VM-Ware (Virtual Machine) Software like VM-Player and install a 32-Bit Operating System too use the old Applications.

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Well, this doesn't sound promising. I just built a new rig and have it moderately OC'd to 3.2 GHZ (55C load with stock voltages) and decided to pick up another 2 GB of Crucial Ballistix Tracers (couldn't resist for $17.50 a gig). I guess what you all are saying is it might disrupt my overclock. I hope to run a dual boot with XP/Vista and figured going to 4 Gig's would be nice. Anyone still able to reach 3.2 with 4 GIG's?Regards, Kendall#1: E6750 3.2 GHZ OC'd/Coolermaster HyperTX2 Gigabyte P35-DS3L 2GB Crucial Ballistix PC6400 Seagate 250GB 7200.10 SATA2 Gigabyte X800XT -Cat 6.12's CH Yoke/Pedals/Saitek Throttle Dual Monitor: Dell 2405/1905 #2: Dell 8400 3.2 H.T. 3GB PC4200 Diamond Xtreme/Logitech X-530's

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