Hi All,I just acquired a factory overclocked GTX 275 to replace my old 8800 gtx. Prior to getting the new card I had recently overclocked my Intel e-6850 core duo from stock 3.0 ghz to 3.6 ghz and experienced only one lock up in three days of pretty intensive FSX use. But since installing the new GPU FSX crashes whenever it encounters heavy traffic or extreme scenery. The question is: Is the CPU giving up the ghost or is the new GTX card the culprit?I did a few stress tests on the CPU and outside of FSX it passed.I wonder whether the GTX, which is factory overclocked from 630 core to 670 and 1000 memory to 1200, is causing the lockups. It's hard to tell. Does anyone know a reliable way to find out which is the most likely? I suppose I could return the CPU to 3.00 ghz or alternatively UNDER-clock the GTX.Or is it Drivers? Can anyone recommend a stable driver for the GTX 275? I used to run the 150.2 's with the 8800 but these are probably out of date for the 275.Any experienced advice gratefully received. Thanks.Rob Young

Hi All,I just acquired a factory overclocked GTX 275 to replace my old 8800 gtx. Prior to getting the new card I had recently overclocked my Intel e-6850 core duo from stock 3.0 ghz to 3.6 ghz and experienced only one lock up in three days of pretty intensive FSX use. But since installing the new GPU FSX crashes whenever it encounters heavy traffic or extreme scenery. The question is: Is the CPU giving up the ghost or is the new GTX card the culprit?I did a few stress tests on the CPU and outside of FSX it passed.I wonder whether the GTX, which is factory overclocked from 630 core to 670 and 1000 memory to 1200, is causing the lockups. It's hard to tell. Does anyone know a reliable way to find out which is the most likely? I suppose I could return the CPU to 3.00 ghz or alternatively UNDER-clock the GTX.Or is it Drivers? Can anyone recommend a stable driver for the GTX 275? I used to run the 150.2 's with the 8800 but these are probably out of date for the 275.Any experienced advice gratefully received. Thanks.Rob Young

G'day Rob,I also have a GTX275 and I too experienced a few lockups on my FSX that didn't happen before I upgraded to the GTX275 (from a 9600GT). What happened is that my flight would grind to a halt with a massive screeching noise and the only way to fix it was to reboot.I seem to have it fixed now but I couldn't say exactly what it was that fixed it. What I did do was update to the latest Nvidia driver (currently 186.18?), tweaked the card settings with the Nvidia Control Panel (no nHancer for me) and tweaked my fsx.cfg file. Took a lot of time, but I seem to have it just right now. I get a good constant 30fps with pretty high settings on the sliders.I can tell you, however, that the trouble is very unlikely to be due to any overclocking because I have my Q6600 OC'd from 2.4 to 3.30 GHz and my GTX275 is factory overclocked, like yours.So, I reckon you need to make yourself plenty of coffee, update your Nvidia driver (watch that you do it properly!) and have a go at tweaking your fsx.cfg file (there are plenty of tweaking guides here).Good luck and smooth skies!

Rob,I'd would run the CPU at default speed (remove all OC settings including RAM timings in BIOS) and use RivaTuner to run the GTX275 at default speeds.If FSX is stable with no OC:ed parts, I'd go on and reapply the OC of the GTX card and test if FSX is still stable. My guess is that your original CPU OC isn't stable enough. FSX is in some ways a better stress test program than OCCT.

Hi again,Thanks both for your input. Yup, it seems the right thing to do is reset the CPU and then investigate the GPU. Actually I would say that my frame rates have never really been a problem - just being a bit greedy here. I've done a lot of personal fsx.cfg tweaks over the years and even with my 8800 gtx have for a long time now had stella fps after the tweaks - well over 180 fps in the default cessna with low scenery and a typical 50-60 fps in the default 737 with everything maxed except traffic. It's always the traffic that hits the most. (I've tried all of 'em: Traffic X, UT2, My Traffic etc etc). The 275 GTX is clearly a better card, with more like 200+fps in default Cessna low scenery and 70 fps with everything maxed without traffic, which is nothing to complain about.Our own Duke, which some find a little taxing on resources, is no problem here. I consistently get 45 fps in the VC and 65 fps in spot with everything maxed except traffic and boats (those boats are a real hog but rarely get a mention in the tweak guides), unless over Manhatten or Heathrow for example.What I have noticed in the past is that if the computer spontaneously reboots it is likely to be the CPU and if FSX simply freezes or locks up with no way out other than a reboot, it is more likely to be the Graphics Card, but I might be misinformed.I did apply the 118.8 drivers and I notice with these that I cannot just force AA and leave it unticked within FSX properties. That seems to be a new barrier in all the latest Nvidia drivers. If I leave FSX AA unticked I get jaggies whatever I over-ride in Nvidia's setup.As for temps, the GTX 275 is remarkably cool - running at around 47-50 with the fan set at 75% -, that's about 20 degrees cooler than the 8800! And the CPU has been running 38 degrees idle and around 47 under load....well within Intel limits, so maybe I need to increas the CPU voltage.BTW my bios will not post if I change the RAM timings. I have to leave them on "auto" to boot successfully.Rob

Hi again,Thanks both for your input. Yup, it seems the right thing to do is reset the CPU and then investigate the GPU. Actually I would say that my frame rates have never really been a problem - just being a bit greedy here. I've done a lot of personal fsx.cfg tweaks over the years and even with my 8800 gtx have for a long time now had stella fps after the tweaks - well over 180 fps in the default cessna with low scenery and a typical 50-60 fps in the default 737 with everything maxed except traffic. It's always the traffic that hits the most. (I've tried all of 'em: Traffic X, UT2, My Traffic etc etc). The 275 GTX is clearly a better card, with more like 200+fps in default Cessna low scenery and 70 fps with everything maxed without traffic, which is nothing to complain about.Our own Duke, which some find a little taxing on resources, is no problem here. I consistently get 45 fps in the VC and 65 fps in spot with everything maxed except traffic and boats (those boats are a real hog but rarely get a mention in the tweak guides), unless over Manhatten or Heathrow for example.What I have noticed in the past is that if the computer spontaneously reboots it is likely to be the CPU and if FSX simply freezes or locks up with no way out other than a reboot, it is more likely to be the Graphics Card, but I might be misinformed.I did apply the 118.8 drivers and I notice with these that I cannot just force AA and leave it unticked within FSX properties. That seems to be a new barrier in all the latest Nvidia drivers. If I leave FSX AA unticked I get jaggies whatever I over-ride in Nvidia's setup.As for temps, the GTX 275 is remarkably cool - running at around 47-50 with the fan set at 75% -, that's about 20 degrees cooler than the 8800! And the CPU has been running 38 degrees idle and around 47 under load....well within Intel limits, so maybe I need to increas the CPU voltage.BTW my bios will not post if I change the RAM timings. I have to leave them on "auto" to boot successfully.Rob

RobJust another idea: try backing-up and then deleting your current FSX.CFG file. FSX will build a new one when you start the application. It's just conceivable that FSX has got itself into a muddle about things.Tim

Hi Rob,I have found that when installing a new graphics card FSX will add it to the fsx.cfg without removing the old one - so you have both. Do a "find" in notepad and look for Display.Device. Delete the old one making sure any tweaks you added to the old are transferred to the new one.

Since you say FSX already crashed once with the CPU OCed I would assume the video card OC is only making the problem worse. However, my 8800GT was overclocked and kept crashing other games I play so I turned the frequencies down to default settings, problems solved.I think the easiest thing would be to set the video card back to standard clock frequencies using RivaTuner and see if you get any more crashes.http://www.guru3d.com/index.php?page=rivatunerOut of curiosity, what make/model of RAM do you have?

Just because the video card is "factory overclocked" doesn't necessarily mean it will work for you that way. I've seen a couple factory clocked cards recently that didn't run stable at their advertised speeds. Lots of factors come into play that may be different than what was on the manufacturer's test bench...power supply voltages, ambient temp, and some bus and memory waveform variations that may be just enough to make the OC fail.As a matter of practice, *anytime* I'm pushing a manufacturer's specs (in this case nVidia, not the video card maker) I start with a known good config at the spec settings, then work up from there a notch at a time. That'd be the GPU, CPU and memory all at rated frequencies, and nVidia version 182.50 drivers. I use the GPU-specific test in OCCT to stress the GPU as I push up the freq 5 MHz or so at a time. Usually the first sign of a speed limit is appearance of artifacts in that test, not a lock-up.As far as the AA goes, nHancer allows a driver-level override of the game's settings...Nick Needham (NickN) has a how-to guide over on SimForums that is the best universal config that I know of. RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Hi Rob,I have found that when installing a new graphics card FSX will add it to the fsx.cfg without removing the old one - so you have both. Do a "find" in notepad and look for Display.Device. Delete the old one making sure any tweaks you added to the old are transferred to the new one.

Yep, saw that. Deleted the old card entry and kept the new one. But thanks anyway.regards,Rob

Answering both Ryan and Bob:I have matched 4 gigs Corsair DDR2 RAM, and intel Core Duo e6850 which is eminently overclockable (got it up to 4 ghz but throttled it back to 3.6 for stability and had no lockups with the previous 8800 GTX, which itself was flawless even overclocked apart from one rare lockup already described).Yes Bob, I think the answer might be to throttle back the GTX 275 until it behaves but this is very disappointing as I'm currently running it at less than the standard speed, let alone slower than the factory overclock settings. I think it definitely is the card and not the CPU since it still locks up with the CPU set at standard. It's a shame because while it is actually running at factory settings it delivers stunning performance until the lock up point. I also notice that it is twice as likely to lock up in night/dusk scenes than in daytime. I don't know if that gives any clues?Incidentally, I ran numerous stress tests on the card using various methods and it only crashed when raising the clocks to almost insane levels. That demonstrates that no stress test is that useful when compared to actually running it in FSX, which is probably the best stress test available in this context. I have a feeling I just have a one-off dud card. Temps are fine, power is fine and I've tried various Nvidia drivers all with the same result. I'm on the point of re-installing the 8800 GTX as it's no fun flying for 20 minutes and then locking up. Prior to this my system was more or less A1 rock solid and never crashed FSX even when pushing it with edits on the fly, extreme scenery detail, and all sorts of chicanery!Cheers,Rob

Answering both Ryan and Bob:I have matched 4 gigs Corsair DDR2 RAM, and intel Core Duo e6850 which is eminently overclockable (got it up to 4 ghz but throttled it back to 3.6 for stability and had no lockups with the previous 8800 GTX, which itself was flawless even overclocked apart from one rare lockup already described).Yes Bob, I think the answer might be to throttle back the GTX 275 until it behaves but this is very disappointing as I'm currently running it at less than the standard speed, let alone slower than the factory overclock settings. I think it definitely is the card and not the CPU since it still locks up with the CPU set at standard. It's a shame because while it is actually running at factory settings it delivers stunning performance until the lock up point. I also notice that it is twice as likely to lock up in night/dusk scenes than in daytime. I don't know if that gives any clues?Incidentally, I ran numerous stress tests on the card using various methods and it only crashed when raising the clocks to almost insane levels. That demonstrates that no stress test is that useful when compared to actually running it in FSX, which is probably the best stress test available in this context. I have a feeling I just have a one-off dud card. Temps are fine, power is fine and I've tried various Nvidia drivers all with the same result. I'm on the point of re-installing the 8800 GTX as it's no fun flying for 20 minutes and then locking up. Prior to this my system was more or less A1 rock solid and never crashed FSX even when pushing it with edits on the fly, extreme scenery detail, and all sorts of chicanery!Cheers,Rob

If slowing the card down solves the problem, I would be thinking heat, unstable/low power supply voltages, or bad card, in that order. If it works OK with an 8800 in the same slot hooked up to the same power connectors, then it's not the power supply, as the 8800 is even more of a watt-eating beast than the 275. If the temps are OK on the 275 when it's hitting the wall, then it's probably time to RMA it back to video card valhalla and try with a new one.That said, I'm assuming you've done the easy stuff like taking it out of the computer, closely inspecting/cleaning the contacts (with light pressure from a pencil eraser), and re-seating the board...and perhaps trying a different PCIE slot as well.Good luck!Bob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Thanks to all who helped. Problem solved. I reset the bios (loading defaults did not properly reset the bios settings). Card is forgiven. It was in fact the bios settings and the overclocked CPU and GTX don't like each other. In retrospect, and this will be a familiar story, I would probably have been better off buying a faster processor, but at least I can now get the card stable in its factory overclocked state and it will probably throttle up even more. No crashes today, so lesson learned...don't mess with the bios unless you are certain what the changes do.On another subject, the reason I stuck with the e6850 CPU is that it is one of the few processors genuinely capable of being overclocked to near enough 4 ghz. When I look at the performance reports of others who have much more exotic CPUs than mine, I'm surprised how slow their systems appear to run FSX compared with mine and I'm wondering whether despite QuadCores and "better" Dual Cores than mine, with their wider pipelines and cache, they are really faster and whether basic processor speed for FSX is still King. Or it could be their FSX.cfgs are not set to run at better frame rates.I'm supporting this idea with evidence: I have a spare rig with an old Pentium 4 runnning at 3 ghz and it still performs well in FSX, and arguably very close to the Dual Core. It too is overclockable and at 3.5 ghz with a current card is still running FSX well.So in conclusion, am I really going to get better performance with a more current CPU?Cheers,Rob

Thanks to all who helped. Problem solved. I reset the bios (loading defaults did not properly reset the bios settings). Card is forgiven. It was in fact the bios settings and the overclocked CPU and GTX don't like each other. In retrospect, and this will be a familiar story, I would probably have been better off buying a faster processor, but at least I can now get the card stable in its factory overclocked state and it will probably throttle up even more. No crashes today, so lesson learned...don't mess with the bios unless you are certain what the changes do.On another subject, the reason I stuck with the e6850 CPU is that it is one of the few processors genuinely capable of being overclocked to near enough 4 ghz. When I look at the performance reports of others who have much more exotic CPUs than mine, I'm surprised how slow their systems appear to run FSX compared with mine and I'm wondering whether despite QuadCores and "better" Dual Cores than mine, with their wider pipelines and cache, they are really faster and whether basic processor speed for FSX is still King. Or it could be their FSX.cfgs are not set to run at better frame rates.I'm supporting this idea with evidence: I have a spare rig with an old Pentium 4 runnning at 3 ghz and it still performs well in FSX, and arguably very close to the Dual Core. It too is overclockable and at 3.5 ghz with a current card is still running FSX well.So in conclusion, am I really going to get better performance with a more current CPU?Cheers,Rob

Glad you found the problem. I'm curious which BIOS setting was dorking things.I just built a core i7 machine that I have running very nicely at 4.4 GHz. Previous machine was a dual-core Conroe X6800 at 3.5 GHz with an 8800GTX--I have a tricked-out Thrustmaster Cougar with Hall Effect sensors instead of pots on it, and still use it for fast-movers in FS9 and helicopters in FSX. There's a considerable difference in performance between the two, and it's not just frame rates and it's not just due to clock speed. On the new machine, FSX runs very smoothly, with only the very occasional hiccup. I locked the frame rates in FSX at 25 (and at 60 in FS9), because I literally can't see a difference when it's higher. But the biggest diffference is being able to roll into a 45-deg banked turn in dense scenery and heavy clouds, and have the horizon pan smoothly without the tiniest a hint of a stutter. I can also go to places where my Conroe would not take me before, i.e. the New York metro area with complex add-ons at KJFK and KLGA, and traffic not only present, but turned up to meaningful levels. Raindrops falling on my head no longer brings FSX to its knees, either.That said, I attribute the gains not just to the much-faster quad-core CPU, but to fast RAM (6 GB of DDR3 at 1700 MHz and CAS 6-6-5-18-1T timings), a fast video card (GTX285 at 675 MHz), and a very fast disk subsystem (an intel X-25M SSD running alone on a JMicron controller in AHCI mode). I'm not sure any one of those would make a huge difference on its own, but together it's very nice.So I'm not sure on the CPU question...better performance isn't always attainable by pushing up one part of the system and leaving the rest. And better performance isn't always measured by a frame rate counter.CheersBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Glad you found the problem. I'm curious which BIOS setting was dorking things.I just built a core i7 machine that I have running very nicely at 4.4 GHz. Previous machine was a dual-core Conroe X6800 at 3.5 GHz with an 8800GTX--I have a tricked-out Thrustmaster Cougar with Hall Effect sensors instead of pots on it, and still use it for fast-movers in FS9 and helicopters in FSX. There's a considerable difference in performance between the two, and it's not just frame rates and it's not just due to clock speed. On the new machine, FSX runs very smoothly, with only the very occasional hiccup. I locked the frame rates in FSX at 25 (and at 60 in FS9), because I literally can't see a difference when it's higher. But the biggest diffference is being able to roll into a 45-deg banked turn in dense scenery and heavy clouds, and have the horizon pan smoothly without the tiniest a hint of a stutter. I can also go to places where my Conroe would not take me before, i.e. the New York metro area with complex add-ons at KJFK and KLGA, and traffic not only present, but turned up to meaningful levels. Raindrops falling on my head no longer brings FSX to its knees, either.That said, I attribute the gains not just to the much-faster quad-core CPU, but to fast RAM (6 GB of DDR3 at 1700 MHz and CAS 6-6-5-18-1T timings), a fast video card (GTX285 at 675 MHz), and a very fast disk subsystem (an intel X-25M SSD running alone on a JMicron controller in AHCI mode). I'm not sure any one of those would make a huge difference on its own, but together it's very nice.So I'm not sure on the CPU question...better performance isn't always attainable by pushing up one part of the system and leaving the rest. And better performance isn't always measured by a frame rate counter.CheersBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Hi Bob,That all makes pretty good sense. The only part I would differ on is frame rates. I take your point about stutters but I never had that problem generally. What I have learned is that if I cannot get the default Cessna to show 200+ fps in modest scenery in spot view there is no hope of getting smooth or decent performance with heftier aircraft and more detail. So when I tweak I start with sparse everything, try to attain those 200 fps and then gradually add bit by bit so I can identify which sliders or settings take the biggest hit.Apart from air traffic, the hits are always ther same in this descending order: Ships, Boats, Autogen TREES, Moving Road Traffic, Airport Traffic, Autogen Buildings. I've never seen any performance hit between highest res scenery textures and 5m, not even a lost frame, but that would not be the case on a GPU with poor memory.Sounds like you have a cracking good system there.All the best,Rob