find this ironic, my $650.00 GTX 580 bought especially for the NGX may be an issue

When FSX came out nobody was even thinking about video cards with 3 gb of memory. Back then you had video cards with 512 meg of ram. Just curious though why did you get the 3 gb version? Are using the card for other programs such as 3d shooters etc? If you just bought the card just for FSX hoping the 3 gb would improve performance you wasted quite a bit of money. Always a good idea to do a little research before making a purchase like that. Guess I will be going with the 1.2 gb GTX 570 and not wasting money on the GTX 580.

We all thought a quad core was pretty extreme back then, now everyone has one, almost everyone. I just look at the 256mb 8400GS in the old PC and just laugh.

Okay my fault your right about the VAS and FSX. (Egg on face now). Just proves my point about 64-bit being superior though. Throw FSX and the NGX in the trash and get a 64-bit Flight Sim! I hear X-plane is coming out for Christmas and that they might make it 64-bit in SP 1.

Well if it's any consolation You had me doubting what I'd said & spent 20 minutes rereading some things. A 64-bit fs would be very nice.To the OP: I'm using 2 1.5gb 580's in sli (surround) and haven't had any issues. I dunno if that would work out the same as a single 3gb card.

well you could not do surround on the single 3GB but I think the SLI would be better even with the 1.5GB.

When FSX came out nobody was even thinking about video cards with 3 gb of memory. Back then you had video cards with 512 meg of ram. Just curious though why did you get the 3 gb version? Are using the card for other programs such as 3d shooters etc? If you just bought the card just for FSX hoping the 3 gb would improve performance you wasted quite a bit of money.

An earlier post from Spiritflyer stated he had a friend who was having OOM issues and upgraded to a 3GB version and the issues stopped.

Well if it's any consolation You had me doubting what I'd said & spent 20 minutes rereading some things. A 64-bit fs would be very nice. To the OP: I'm using 2 1.5gb 580's in sli (surround) and haven't had any issues. I dunno if that would work out the same as a single 3gb card.

May have to downgrade to the 1.5GB version?

Well if it's any consolation You had me doubting what I'd said & spent 20 minutes rereading some things. A 64-bit fs would be very nice. To the OP: I'm using 2 1.5gb 580's in sli (surround) and haven't had any issues. I dunno if that would work out the same as a single 3gb card.

No, it´s not the same as one 3GB. FSX only use one Card, even if you had 100 of them. / LeffeEDIT: ...and what I heard, a SLI isn´t so good in FSX either as only one Card. But of course if youuse other games, then it´s good to have it in SLI I guess.

An earlier post from Spiritflyer stated he had a friend who was having OOM issues and upgraded to a 3GB version and the issues stopped.

Not sure how that could be if the VAS comes in to play cause it means FSX only had 1 gig left to work with? Should be the other way around, if he put in a Video Card with less Memory on board, he would have more for System Memory FSX to use?

An earlier post from Spiritflyer stated he had a friend who was having OOM issues and upgraded to a 3GB version and the issues stopped. May have to downgrade to the 1.5GB version?

I would, but I guess that´s no good feeling, when paid so much for that Card. Sorry./ Leffe

No, it´s not the same as one 3GB. FSX only use one Card, even if you had 100 of them. / Leffe EDIT: ...and what I heard, a SLI isn´t so good in FSX either as only one Card. But of course if youuse other games, then it´s good to have it in SLI I guess.

Well that's good news about the single card bit. I wasn't sure how that worked & was afraid mine were adding up to 3.5gb (tiny 3rd card for extra monitor, non-SLI). Good to know that isn't the case. You're right about the SLI. It doesn't help FSX & has the potential to harm performance due to the slightly higher CPU load when using SLI. I only use it to span 3 monitors, not for performance. To the OP: If you bought that card to run the NGX go ahead & give it a shot! Worst case you just walk into a video game shop & offer a trade. I can almost guarantee one of the employees will have a 1.5gb 580 in their home system, even on minimum wage. They might even give you a few bucks or some in-store discounts to help make up for losses. Happens where I live all the time. Hook somebody up 1 time in east Texas & they'll sell to you at-cost for a year.

Not sure how that could be if the VAS comes in to play cause it means FSX only had 1 gig left to work with? Should be the other way around, if he put in a Video Card with less Memory on board, he would have more for System Memory FSX to use?

Remember, its not the entire 3GB that comes off the VAS, only the amount that is actually used by FSX

Could be a potential issue. Even though you're on a 64b os, fsx can still only use 4gb. If the 3gb on your video card is part of that you could run into problems.

100% Correct. FSX is a 32 Application, and as such can only uses 4 Gigs, on a 64 Bit OS. However, it can use ALL that 4 Gigs, as it does not need to share any with the 64 Bit kernal.( on 32 bit machines, FSX + Kernal use 4 gigs )

This is a very interesting thread... and pertinent as I am about to build a multi monitor system for a simpit for DCS:WH and FSX. I am planning on two 3gb GTX580s mostly for DCS. So the questions is, can you limit the amount of VRAM that FSX uses, and potentially reduce the likelyhood of an OOM... Effectively trick FSX into thinking the 3Gb card is a 1Gb or 1.5Gb card?

Just get 2 1.5GB 580's. More than enough unless these 3 monitors are extremely high resolution or/and you're running crazy high AA

so let me ask you folks currently I am stil running my gtx285 but very shortlyI will be updating now to what gtx 1500gb 03r 3,000gb. Currently runing windows 7 64 bit on 27" 6gb memory what do you suggest on the 580 gtx 1,500 or 3,0000 firmy system ? I want to have a good ride. let me know please your recommendation.

Some differing opinions here. I find this ironic, my $650.00 GTX 580 bought especially for the NGX may be an issue. This is why I would like comment from anyone who has a 3GB GTX 580 and has used it with the NGX.Maybe the recommendation from PMDG should be a card with no greater memory than 1.5GB? Andrew Dixon

I would be interested in hearing this as well. I was debating between the two after I bought my high res monitor. I decided on the 1.5GB version but I have heard many differing opinions around here...