I've been running a dual boot XP/W7 install for awhile now but TBH W7 always leaves me with a feeling of indifference, there isn't anything that makes me feel I must switch to it from XP permanently. Occasionally I boot into W7 just for testing stuff and general poking around but am quite happy to go back to XP for my main uses. Anyway awhile back (can't remember which build, might of been B60) I tried rF2 in W7 and although I haven't got any hard numbers to back this up I remember it performing pretty much the same as XP. Once again I was quite happy going back to XP knowing I didn't appear to be missing out on anything. At this time I was running a dual core E5200@3.3GHz and 3GB DDR2 with an 8800GTS 512MB video card. I've since upgraded to an i3-2120 with 8GB DDR3 (bit of a waste on XP I know) and as of yesterday I picked up a 2nd hand GTX470. Was actually on the lookout for a cheap 460 1GB but the prices they (and video cards in general) seem to go for.... I mean don't people look at how much stuff is brand new thesedays. Been having a few problems seems the guy I bought it off has flashed the bios from another brand of oc'd 470 and I'm suffering with artifacts and occasional lockups. A small bump in GPU voltage and stock clocks seems (fingers crossed lol) to have sorted this out (still testing). Getting back to rF2 (finally lol) I ran my usual standard test (most settings OFF or LOW as had been dictated by the 8800GTS) with the 470 for comparison and frankly it's disappointing. Only recorded a paltry 19% increase in average fps and 35% increase in minimum fps. Just tried with the 470 on W7 and this time there's a difference from XP, still nothing to shout about though. Average fps up a furthur 25% and minimum up by 23%. The idea of buying this card was so I could turn up some eye candy as the 8800GTS on LOW settings was providing more than adequate framerates already. Problem was all my recorded testing has been done (by necessity) on LOW settings, then I remembered I'd posted in a rF2 Benchmark thread and I had numbers for that. I've ignored my 'full settings' test results as the 8800GTS was so overloaded and can't do MAX shadows properly. I ran the 'playable' settings with the 470 (on XP) and WTF there was hardly any increase at all over the 8800GTS!! We're talking increases of 0%/5.5%/18% (min/avg/max). However running the 'playable' settings test on W7 resulted in increases of 160%/109%/68% (min/avg/max). So there I have it, running a 470 and 8GB of system ram on XP is such a waste, shame I find W7 so meh (I believe that's the current phrase lol) but the time to move on really has arrived and reluctantly I'm going to have to bite the bullet. Just to add XP is 32bit and W7 64bit.
My first thought is that the RAM limit on a 32-bit OS includes video RAM. So by adding 512 memory (or more) on the video card, you are reducing the available amount of system RAM, theoretically, by that same amount. It's not always a perfect one-to-one, but try adding a 2GB video card to an XP system with 4GB RAM. You will see the available system RAM reduced to just about 1GB.
I did do some reading about this stuff awhile back but it's difficult to come across any authoritive answers. One of the more plausible (well to me) ones that it's to do with DirectX 9 on XP and that's why 32bit W7 shouldn't suffer to the same degree. But if you're going to W7 unless you've got a good reason not to you might as well go 64bit.
Have you edited your boot.ini? (right click my computer, select properties, advanced tab, click setting on startup and recovery, click edit from starup and recovery dialog). I have these after my OS mumbojumbo at end of the line /3GB /USERVA=2500 That allows large address aware software like rFactor2 to access memory beyond 2GB limit. You probably can't go to /3GB /USERVA=3000 as gfx card takes part of memory and that might lead to some odd behavior when kernel runs out of available ram, but as I have 8800GTS 512MB version and WinXP with 3GB ram, I have been using 3000 option without huge issues so far, but I might got with 2500 for a while and see if random GIMP crashes will get solved by that. You can copy and paste more of those lines and add different number, keep in mind that too large number might prevent winxp from booting, so better to have several lines with enough low numbers so you can make it start in case of problems. Also that added parameters made possible to do mapping in max without constant error messages of out of memory. With your 8GB ram, I recommend to get some nice ramdisk software that can utilize that beyond 3GB limit and put swap/temp on ramdisk, which should make things run really smooth, maybe rFactor data folder could live there too for really quick loading? It is shame that WinXP 64bit was so bad as I would really need 64bit system, but even with high swapping this WinXP is so much more fluent and faster to use than those more modern 'user is idiot' operating systems that I dislike so much.
Amount allocated system RAM for gfx may be changed by various 3rd party software (for tuning/over-clocking)
Windows XP x64 is really not Windows XP at all: It was built with the Windows Server 2003 kernel and the XP GUI was added (along with a few other things from XP). Windows XP and Windows Server 2003 was the last time the Microsoft separated their kernel between client OS and Server OS. Starting with Vista onward to Windows 8, the client and server OS share the same kernel. If you look at the service packs released, you will see the service packs for Server 2003 are the same for XP x64, but not XP.
As long as you are using Windows XP 64-bit edition with SP2 already integrated (XP/SP1 64-bit edition had an issue with HAL) there shouldn’t be any issues, I haven’t had any anyway. Windows XP 32-bit is useless with up to date hardware with 4GB+ of system RAM and 1GB+ of dedicated RAM on the GPU now the norm. That being said on fresh installs of Windows XP/SP2 64-bit and Windows 7/SP1 64 I’ve seen better performance with Windows 7 in just about every sim/game I run, not to mention that almost every new sim/game I run now uses DirectX 11 which rules out using Windows XP anyway.
