I have 2x GeForce GTX 760 x4GB = 8GB...Nearly five years old.
For twelve months on and off,I have been getting split second flickering of the screen in game and out of game and even in this forum.I got an idiot or should I say he was smarter than me because I paid him and he couldn't figure it out from Geeks R Us.I have a suspicion that it is one of the cards playing up but my question is....How long does it take to blow up the card? If it was weakening,would it take this long?

There is no exact time limit for when a piece of hardware is going to fail.

Likewise, there is also no exact procedure that sets out the precise means by which a piece of hardware will fail.

All hardware fails eventually. The older a piece of hardware is, and the more hours of usage it has had, and the more heat it has generated and/or been exposed to over time, the more likely it is to fail.

Have you checked that each card is correctly seated in the PSI slot and running a heaven benchmark?

Have you tried running each card individually and running a heaven benchmark on each separately?

Do you have other monitors as it could be the monitor? Again benchmark because if it can do the benchmark you can rule it out being the card

It's a frustrating investigation of trial and error

"I have 2x GeForce GTX 760 x4GB = 8GB"

Just for the record, that's not how it works with GPU VRAM. It doesn't really stack, you're still limited to 4GB VRAM, you just have more visual processing power, at least when SLI actually works.

As for your problem, I'd remove the GPUs and then test them one at a time. It could be that only one of them is faulty. However, given the age of these, you may be better off with a single, more modern GPU.

I had one many years ago,in a 386 or 486 and it started playing up and within a week it was history.All my pc's since then have been trouble free but it does play up more on hot days. Thanks for the suggestion but I am not a computer mechanic but if someone that supposedly is a computer geek and he can't figure it out in a house call then like you said it's bloody annoying and maybe it is the monitor as that also crossed my mind.

Thanks for the help but you are speaking in a foreign language as far as testing one at a time.Can I ask why everything says on pc 8GB? And it's only operating on 4GB as I can see where a strap connection is running from one to the other.This is way over my head and I think I'll wait for the crash.I refuse to take it to a pc repairman as they are bigger crooks than me.

Neither am, I don't have technical knowledge, but I know how to problem solve. There's nothing technical here, it's just stages of problem solving.

We don't know what this supposed computer geek did or if he simply ripped you off. What did he say he tried doing? Simply put, if you want something doing properly you have to do it yourself.

First step tell me is the flickering constant or does it come and go? Does your PC ever crash?

Now download and run this:

https://benchmark.unigine.com/heaven

Run it for 60 minutes and let us know if your pc crashes or visuals gets worse

He stood and looked at the pc and the problem,then he saw the problem after a couple of minutes and said it might be that geforce may need updating which he did.The flickering might be every minute or so on hot days and cool days it is much less and sometimes doesn't happen.It started while playing Anno 1404 Venice and became quiet annoying so I tried older games like M&M and it never appeared so I figured it may be a card.It even stopped for a month or so and I thought whatever it was it fixed itself.I had a lot of trouble with the internet cutting in and out around the same time and thought it might be that.Turned off the internet and it continued so I thought it as an illumination but I am still suspicious that it could be that.The GEEK said he could probably fix it but would need all day,so after his hour visit was up I paid the ($168) and politely showed him the door.In hindsight and my figuring he was a bit knowledgeable but a complete waste of time and money and wouldn't recommend them to my worst enemy.

The flickering is usually every minute or so and last a split second.Sometimes it flashes with coloured lines and that made me think it is the graphics card but most times it's like interference.The old TV's many years ago used to suffer from interference when the neighbor used a drill or something electrical and it reminds me of that.

I realize this is extremely hard to explain or get help over the internet but I will run that program tomorrow and see what happens.thankyou.

Oh,I don't consider the GEEK as a ripoff but just another lesson in life:)

Linus tech tips did a YouTube video that demonstrated that older, used graphics card problems are more likely software related than hardware failure. Try doing a fresh install of the latest drivers and see if that helps.

So I'm guessing it's constant even when web browsing now?

It could be:

Monitor
Cable
Drivers
1 Card

Did you try running heaven bench? You can even play your most graphically demanding title instead. If it doesn't drop out then I'd guess it probably isn't one of the cards.

Do you have an old monitor and cable? If it's the same on a different monitor with a new HDMI cable you can rule out the monitor and cable.

If you type 'device manager' into windows and open it. Click on display adapters. Click on your graphics card, click update drives.

Failing all those things remove 1 card and see if the issue persists. If it does switch the graphics card.

If you try all those things you should be able to identify the problem I'd think.

If it is the card there are great deals on Vega 56, 580 and 570 to be had at the moment, depending on your needs. But you don't want to get a new card and realise it was your monitor all along.

Are you talking about RAM or VRAM? Most games require 8 GB RAM because the operating system takes up a lot of it. While there might be games which ask for at least 8 GB VRAM, I doubt that is the majority.

As to the rest if it, split second flickering. I've heard that can be an issue of SLI, but it could also be a bad video cable. That doesn't sound like your video cards dying to me. Flickering is usually related to a bad cable, drivers and refresh settings. This is opposed to "artifacts" that will appear under high load and are a clear indication your card is dying.

1) Check the connection at the back of your monitor and where the video cable goes into the graphic card. If you have a replacement, or know someone you can borrow a replacement cable to test, we can eliminate that as a source of the issue.

2) Try turning VSYNC on and off in your video settings and see if that makes a difference.

3) Another shot in the dark, but is everything plugged into the same power strip? If you have another outlet nearby, try plugging your monitor into a separate outlet from the computer.

Edit: What you said about your neighbor's drill and old TVs is very similar to what goes wrong with video cables. The shielding on the cable can crack over time from age and back and forth wiggling over time allowing interference from other electrical devices. The intermittent nature, such as the fact it can go away for months at a time might be the cord hanging in a "good position" which doesn't expose the crack so much. You can also try "wiggling" the cable itself, especially where it connects to the computer and then your monitor. If the problem gets worse from wiggling, it's definitely the cable. In the short term, you can play around with the way it sits and might be able to make the problem go away temporarily until you can get a new one.

Too much dust or problems with the power supply are also possibilities. Power and data cords and cables would also be my suspects no 1. Add the places where their connectors are soldered to that same group as modern solder can crack after a relatively short time.

Okay,ran Benchmark for a good hour and no crashes.

FPS: Stayed on 60 all the way except when scene changed and instantly went back to 60.

Graphics: Was a constant 1202 MHZ on High settings and Ultra.

Memory: 3004 MHZ and never changed.

Temperature: Top card ran from 60c to 79c......Bottom card was running 2 to 3c higher than other card and this was constant.

No sign of problem,Loaded Skyrim and still no problem but couldn't have full control of game as Benchmark used same keys.The FPS dropped but I expected that running two programs at the same time.

Cable was changed a few months ago and still had problem.Have cleaned dust and pc with a hair dryer,so it's pretty clean.
Cant seem to locate the Benchmark save files and have looked in most folders associated with it.

Thanks for the help,everyone as it is appreciated.I will see what happens in the future and try and figure it out and in the meantime I will update all drivers and the driver for GEForce is only one behind latest one.Constant updating GE and still problem was there so I don't think of it as a problem solver.After all they come out with updates every couple of weeks.

Just an after thought,could it be a driver for the modern as it is one that windows says is up to date.Modem is a few years old but will be changed in a couple of weeks when NBN is hooked up.I will keep an eye out for any changes after NBN is hooked up.

Hmm... only if too close to your pc or cables.

Yeah,that helps.....What?