It's more a question of whether, if this is a quick fix via GPU replacement with a cheap card to keep it ticking over, it is worth waiting for this new Nvidia tech I've heard about (Pascal), or to just get a new top-end machine now, as I want my PCs to last - my first one went for 9 years, this one just passed 7 years, I don't really want to be replacing again in 4-5 years time.

My current PC was built at the end of the Core 2 architecture (I could have chosen from the at-the-time brand new Core i processors but decided not to based on price and performance) and I've been very pleased with how well it has performed and lasted, and a hardware failure at 7 years isn't bad going. Of course, I knew that my upgrade path was pretty much non-existent, as my motherboard is socket 775 and DDR2 RAM and the new Core i processors were on a different socket whilst RAM was moving to DDR3.

So if I get a new top-end PC built to replace my current one, what kind of lifespan could be expected? Would the upcoming Nvidia tech (Pascal) result in enough of a performance increase to make machines need to be replaced even earlier?

Your graphics card passed because of overheating I am afraid. It looks to me like a bad memory chip, but can be gpu as well.. In both cases you can't do much about it.
You can try cleaning up the card, check for any fat capacitors (and replace) and underclock it..
Then get a cheap* card (or borrow one), wait a little bit and do a wise shopping if you ask me.

*bloody hell..

The question is why, except for a principle? Your PC was behind the curve a year after you bought it and has been old tech for a while now. So why not buy something a little cheaper and keep it for less, perhaps upgrade the graphics card mid-way through its life?

Well, my current one cost me around £1600 at the time I built it, including peripherals, so taking them off (as I'll be keeping stuff like the monitor, printer, keyboard, mouse, etc), let's say £1400 (very rough estimate as I don't have figures to hand). So that's £200 per year for the PC itself. And it's handled almost everything I've wanted to run on it, it is only over the last year where there have been games I can't physically run, but with the backlog I have that I can run that hasn't been an issue.

So, if I were to change PC every three years, then that's a spend of £600 each time. Is that do-able? Wouldn't it always be running games in the realms of medium to low, never ever playing anything in high settings? I know my machine hasn't been able to run at high for a while, but when I first had it it could, so it's moved from high to medium, and was just getting into the medium to low specs on some games I play (like KF2). And then there's the hassle of disposal each time a new one is bought (I've no space for more than one desktop where I am).

Anyway, my techy friend says he'll pop over one of the evenings either with a spare GPU (if he has one) or his current one, so that we can then test whether it is indeed my GPU that is failing here. If it is, then I could replace it with a cheap one to give me time to research a new build. In any case, I think it is going to be a new full PC replacement soon.

A work colleague has said to go with a custom build via a website - he uses Overclockers (I have bought components from them in the past) - rather than build it myself due to there being a high RMA rate on some components like CPUs at the moment.

Of course, I haven't taken inflation into account, or that I might be willing to spend a little more than I did last time. Though I hadn't been considering a PC replacement until now, now that mine is broken.

Looks like Windows might be failing to load the drivers of the GFX, and loads a generic VGA driver instead. Result : you still read something, but you get parasitic dots. That also explains why safe mode is still there. It it's that, it's usually because the GPU itself has issues, or because something like a capacitor is dead on the graphic card.

Replacing your GFX might be worth a try. For 60£ you could get a radeon R7 250 or a Geforce 740. Nothing spectacular, but enough for a waiting solution , leaving you the time you need to have the new PC you want.

Your build was very, very similar to mine! My MOBO just bit it. So it's the end.

Anyway, we're brothers or sisters in PC-death!

I just bought an LGA1151 MOBO (MSI Mortar B150m) and the weakest Pentium (G4400 -- cheap) which is a huge improvement on my last system. And 2 sticks of DDR4-2133, 4GB each (doubling my RAM).

In 5 years, I can pop out my G4400 and pop in a speedy i5 or i7, which at that point will be much faster. My only downfall is that my RAM won't be any speedier, but reports are showing only a 6ish% framerate change from 2133 to 4000.

So get an LGA1151 so you're set up for a future improvement if you don't want to spend the big money now.

Ok, I was wondering if you had a 'stock' psu.

Then, I saw your screenshots, if you have 'geometrical' artefacts on the display, it is probably tied to bad memory reads on your GPU as you suspected. If you constantly see those even after a complete clean up of your GPU you can worry (dust can be responsible of short circuits on memory pins).

We are. But sometimes a therapeutic effort is worth a try. Not so long ago, my computer started to reboot from time to time, then very frequently. Tests I did showed a pad picture : memory errors. I changed the RAM for a pair of reserve sticks, slight improvement, then worsening again. In the end replacing the ventirad , the ram and removing tons of dust cured the system. No crash for 3 months.

It's a solution, but the OP would end up pairing latest gen CPU, GPU, RAM and Mobo with 7 years old PSU, HDD and optical drives.

I would either go for the cheap GPU replacement or go for a new system, possibly ( if money is a constraint) indeed with a mid-range CPU ( i3 6100 for instance) and a lower upper tier GPU ( Geforce 760), leaving the option of a nextgen GPU and of a CPU upgrade when doind a midlife update in 3 years time.

Well, this PC, when configured with a 120GB SSD and 2TB HDD costs £781.20 in VAT. (You could upgrade it to a GeForce 960 for another 22 quid or a 4GB one for 36). So you have an £800 PC that by your calculation should last 4 years, and it would run most games at pretty high quality and decent frame rate (especially if you take the 960 route).

Then in 4 years you could buy another sub-£200 card and play most games at decent quality for another 2-3 years. So you'll end up with an even cheaper system in the long run.

Still, it's up to you. It feels to me like you'd be perfectly fine going with a mid-range card, and in fact that's pretty much what you did last time. Only this time the high end cards are meant for higher resolutions than 1080p, so you can buy cheaper and still be about the same place you were last time you bought.

The XFX GTX 260 Black Edition was actually almost competing with the stock GTX 280 at the time I bought it, due to the factory overclock of the Black Edition, so it was a little better than mid-range, but also not at the top.

Fair comment about the resolution, though. I only have one monitor and that is 1680x1050 (though I will look to get a 1920x1080 next time). And there is a noticeable price difference between the 80s and the 60s.

Just been looking at PC builds on Overclockers and Scan Computers, and I feel I have a lot of research to do to learn what components are out there now as I've not been following PC component news since my build 7 years ago.

Hello sibling! :)

Just noticed that I don't appear to have listed my motherboard. It's a Gigabyte GA-X48-DS5.

One of my current PC building questions is about whether a motherboard should have onboard graphics as a backup for just these scenarios. My current one doesn't, but my work colleague says that most new ones do. But do gaming quality motherboards bother with the onboard graphics as an option as the first custom build I designed on Scan Computers (just playing about with parts and prices at the moment) didn't have any onboard graphics.

Most new motherboards actually do not. The intel chipset for all LGA1151-format microchips have it built into them now. So you'll have on-board no matter what now.

Just had a look at some socket LGA1151 motherboards and yes the had onboard graphics. But, one had DVI and VGA the others had HDMI and DisplayPort. My monitor is too old for those new ports, it only has DVI.

There are adapters that go back and forth. DisplayPort is very adaptery. I'd get the newer one, personally.