Dave, my system is similar to yours, the difference is my overclock is not as extreme and you have a mas macho video card.I've seen no stability problems with fsx sp1, or any other benchmark.Seems to prove that sp1 can be successfully operated on an overclocked machine.I should add that my overclocking project did previously show more headroom in my box than just 3ghz. In fact 3.2 was quite stable for me. Of course this is still at stock vcore. I just always back off some once I reach a stopping point....kind of like putting a quarter turn back in with the mixture knob when the rpm drops.Possibly, sp1 is using that extra headroom, and my stability now at 3ghz is equivalent to the stability pre sp1 I noted at 3.2ghz.BobIntel D975XBX2/Intel Core2Duo E6600@3ghz/Arctic Cooling Freezer 7 Pro/ ATI x1900xt

>>>>So far, I have not heard from anyone else that SP1 +>overclock>>is causing problems...>>>>Rhett,>>Just read Al Jordan's post in this thread and you'll find one>;-)>>Ulf B>At the time I posted that, I had not yet read al's post. ;)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

I think the problem is the system is timing out loading textures. I added the Terrain time out line that Phil Taylor recommended and that took care of the problem for me. Try it. Its in his blog.I changed mine to 60.

I call 600MHz more than a modest overclock, but it seems the E4300's do it with ease :) I take it you ran the stress tests on both cores at once, and verified via the system monitor? I didn't get errors stress testing until I maxed out both cores for about an hour. Now that SP1 makes use of both cores, this could be causing the problem.Also, depending on your location, it may be getting a bit warmer out, so overheating could be a concern as well.Paul

Very interesting point! No, this is my first dual core CPU. It never even occured to me to stress both cores. How do you do that and with what? Prime95, Orthos, etc? How do you force the second, simultanious test onto the second core?

well it seems there is something to it. I used to OC 30% and run stutter free. SP1 brought me massive stuttering in regular intervals, every 3 seconds or so ... removed the OC and I get the same frame rates without the stutters. Seems that full load on both cores and OC don't mix :(There is a new parameter in the fsx.cfg called ProcSpeed=####. Might that have something to do with it? ==Marten:Weber==P-D920 3.3MHz 2GB RAM WinXP ATI X1900+1024MB 2xSATA250 2xVIEWSONIC 19"

For me, it was more about dropping my FSB and increasing my multiplier back up. Also the memory timings had to be relaxed from 4/4/4/12 to 5/5/5/15 (rated). My CPU OC speed is still where I originally had it (~ 3.3Ghz) before SP1. So, I think the loading of both cores puts a greater strain on the FSB bandwidth. When I initially saw my issues, I was sitting in the Baron at the end of a Atlanta runway, no AI, on a clear day, with minimum sliders, and I got a max of 4 FPS and serious sound crackling from my XFi-XtremeGamerPro sound card.

Yeah, I'd definately attribute your instability to your RAM.I've been working with my system, which has Kingston HyperX 800 MHz RAM, and my system was sort of unstable at 3.11 GHz with a 667 RAM divider setting (RAM at 854 MHz) and 4/4/4/12/15.6 timing. So last night I loosened the timing on the ram, dropped the divider to 533 and memory at auto (5/5/5/16 731 MHz), and upped the speed to 3.29 GHz and the system made it through the night without locking up. I'm going to try to up the speed some today. At 3.11 GHz, my temps under load (FS SP1) were about 42C system, 40C CPU, 48C Northbridge. At 3.29 GHz, my temps are 44/42/55, though I saw CPU go up to 50C last night at this clock. Ambient is a little cooler this morning.FPS in the Nashua, NH to Stow, MA area is around 18 - 40.E6600, DFI Infinity 975X/G, EVGA 8800 GTS 640 OC, Kingston HyperX 800, Aircooled Zalman 9700, Antec TP3-650W PSThomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

Now that both cores are running threads, timing between them becomes very important, it's possible when you over clock a dual core, that it's throwing the cores slightly out of sync so one processor, has to wait for the other to pick up on what it's doing, causing the stutter, or maybe more likely it's generating collisions on the bus!! Phil, said this was a possibility when using multiple cores. I don't over clock my system, and get good stutter and blurry free performance.

Sounds like you were having a problem with heat.That'll definately cause stutters.Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

As I noted above, I've overclocked mine now to 3.34 GHz with memory at 731 MHz (divider 533 and memory set to auto (which ends up being 5/5/5/15/2T)) and temps consistently in the low 40'sC of the CPU, less than 50 on the Northbridge, and I am completely stutter free and smooth, with FPS locked at 40. I get anywhere from 18 to 40 around Nashua, I'll try Boston and NY tomorrow.I feel like there might still be some overhead there.Watch those temps!Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180

I've disabled the OC AI and set to constant +30% OC - running smooth again. AI OC used to switch into OC when processor load was high. ==Marten:Weber==P-D920 3.3MHz 2GB RAM WinXP ATI X1900+1024MB 2xSATA250 2xVIEWSONIC 19"

I found that by lowering the value in ProcSpeed= manually I achieve smoother simulation, as both cores aren't always maxed out. ==Marten:Weber==P-D920 oc3.64MHz 2GB RAM WinXP ATI X1900+1024MB 2xSATA250 2xVIEWSONIC 19"Best AI available today: www.world-of-ai.com

On the subject of power consumptions, if you're running two cores and one video card, a 550W may do it provided that it's not the $80 sunday special.My FX-60 CPU uses up about 140W (poor thing is running water cooled at 0.2v over vcore to stay stable at 3GHz up from it's normal 2.6). Key thing here is memory is running 1:1, so that Corsair is running also a bit higher voltage wise to keep the bits in order.The 7900GTX cards use up 200W each at full blast. It's amazing to me that a chip less than 1cm2 eats up that much power (well, ok, there's the memory to go with it too I suppose).My PSU is a 650W with high amps on the main racks, and for the first time in FSX its fan is really cranking out the juice. They always say that as CPU density increases, the power requirements drop. That's true, but somehow that is always negated by the desire to run at higher clock speeds, and memory requirements always seem to double.Thanks for the tip on the processor speed, I'll try that to see if that helps being smooth. I've got the system where I think I want it, but there are so many parameters to the problem that no one magic bullet seems to exist.Cheers,Etienne

how long did you leave Orthos running (Blend mode presumably) to check stability ?I normally find it has to be run for about 8 hours to guarantee stability 24/7 in Vista and processor intensive games like FSX etc.I get different failures at different times in Orthos, like if it fails within the first 2 mins its either the RAM or the CPU, fail point at 30 mins- normally too low a Vcore, fail point 1 hour, same, fail point at 7 hours a gradual over-heat - or too low a Vcore.My E6600 is overclocked to 3.1 gig and I haven't had any more problems with SP1 - in fact less.Whats your max core temp on your CPU when running Orthos ?Mark.