@locrieth - Too true!
Right, this is my actual spec:
2Gb Crucial PC2-4300U DDR2-534
Intel core2duo 6300 1.86Ghz
Radeon HD 5770
Kingston ssdnow 300 120gb SSD
Regular 1.5tb SATA hdd
ASUS P5B-E
Need to check if I can do anything with this setup to last a little longer
Your motherboard supports DDR2 800MHz memory, 8gb max though you could be spending more getting 4 2GB sticks of DDR2 800 than you would spend buying new DDR3.
The motherboard also supports Q9550's and such, but this would cost as much as a G3258, maybe more, but not clock as high in single thread applications. I doubt the motherboard would allow a decent overclock on an LGA 775 cpu.
I had the same CPU as you, on an Asus P5QL-VM EPU LGA775 MicroATX motherboard with Corsair XMS2-6400 4GB (2x2) 800MHz DDR2, it was pretty limited, certainly not something I would add a GPU to for gaming. Even if I added an Intel® Core™2 Quad Processor Q9550 and Corsair XMS2-8500 8GB (4x2) 1066MHz DDR2 it would bottleneck an MSI 7950 and the bios would offer limited OC potential, which itself would need a reasonable cooler.
Your PSU dates from around 2006 also?
I think your hard drives are fine, you would probably even get by on medium settings with the HD-5770 on a 1080p resolution, with a G3258/Z97 combo.
May I ask what case you use and CPU cooler?
Could be worth looking for a case/psu/cooler/motherboard/cpu/ram, and using your current hard drives and GPU, then later upgrade to the best single GPU you can.
To give you some context, I have three old LGA 775 systems, two were capable of gaming, these were both good overclocking P45 chipset LGA775 motherboards, Asus Maximus II gene and a Gigabyte GA-EP45-DS3P. I have C2D E8500, C2Q Q9550 CPU's, 4gb of PC8500 Dominator GT, 8gb of Corsair XMS2 PC8500.
Bequiet, Noctua, Scythe coolers. And used a 630w Bequiet and 650w Seasonic PSU's with them.
The biggest GPU each would run, though I feel the old systems limited performance, was the MSI Twin Frozr 7950, that and an SSD made the biggest difference. I also have AMD HD4870 and HD5750 GPU's that work ok on many games at medium settings, but really are not up to much when compared to newer budget GPU's.
My Asus P5QL-VM sits as a plaything for server and linux software, using it's on board GPU, I had upgraded to a Pentium 6300 in that, it's not worth using for games, but it now has a Q9550 and 8gb Corsair XMS2 in it after my Gigabyte motherboard got damaged beyond repair.
I saw absolutely no point buying a second hand LGA775 P45 motherboard to replace that, I bought a very capable Gigabyte Z97X-SOC Intel Z97 motherboard on yesterdays today only deal for £105 to replace my blown Gigabyte LGA775. Every replacement P45 with the same features as my old motherboard were going for almost as much as a new Z97 motherboard anyway. You would have to have a screw loose to buy old LGA 775 stuff at the same price as new up to date Haswell kit.
I will be buying the G3258 to replace the Q9550, and adding 8gb of Kingston DDR3 2400Mhz memory to replace the 8gb of DDR2 I had.
Had my Q9550 stopped working, I would have moved to Z97, if my 8gb of DDR2 had stopped working, I would have moved to a Z97 system with DDR3.
Old kit is simply priced too high for the performance it offers in comparison to newer tech and current pricing.
I had intended to use my Gigabyte GA-EP45-DS3P/Q9550/8gb XMS2 DDR2 until Skylake had been out for a few months. Now I plan to use the Z97/G3258 for a year.
I honestly think a Z97 motherboard such as the Gigabyte you originally chose, with the Kingston memory, and a G3258 will provide you with a decent platform to upgrade upon as your finances allow. Skylake will be a whole new system, DDR4 etc, but I bet we will see imorovements within six months of release, as such buying a Z97 now is worthwhile instead of waiting a year with such a low spec system.
An E8500 overclocks well, but you have to consider the cost, including delivery, of an old CPU like that, usually £18. Or a Q9550, usually £65. Usually DDR2 PC6400 and PC8500 ends at around £35 delivered for 2x2gb, around £60 to £70 for 8gb of second hand DDR2.
None of these can match a new Haswell chip, or DDR3, and the Pentium G3258 has plenty of reviews showing it bench and offer exceptional performance and overclocking ability which make it a viable i5 alternative for a budget gaming rig for many a new game.
Now to me £18 is a lot when a better CPU is only £55 new. £60 on an old Quad cpu is a lot if a new £55 dual core betters it in most benchmarks.
When you start looking at dual graphics cards it is not all roses either, you could be looking at 750w to 1000w power supplies, new bigger cases with stronger GPU cooling ability, and not all games benefit, or run smoothly.
If you have a 1080p monitor, you are simply better off with a single card in most situations, I run a 1080p 120hz gaming monitor, I have two MSI 7950, but the second GPU is never in there, it's always getting passed around other systems.
There is also an argument for current tech. Right now the AMD 290 and 290X offer quite simply the best bang for buck, the Nvidia 980 does not offer the extra expense worth of performance, though it does offer superb efficiency, for 4k gaming two 290 out perform two 970, and two 290X perform as well as two 980 if not better.
Any crossfire/sli set up will need a new PSU, and people quote efficency. But the fact is, you may save power with Nvidia, but there is little cost difference between a 750w/850w/1000w psu, all are as efficient as each other with such loads as that optimal efficiency is always within that middle 3rd, and the cost of the electricity difference is neglegable as rarely will anyone be gaming at 4k for 24 hours a week every month within that year to meet the quoted expenses some benchmarks make up.
It is the same with games, in the past if you wanted the best game rig, you went with a dual core, because they clocked higher than the Q6600 and Q9550 quads, no game was benefitting from more cores. Roll on half a decade plus. Multi core gaming is still in it's infancy, most games are ported from cosole titles, and many see no benefit over 60hz.
Which is why the G3258 offers such great performance for a budget gaming rig for many purchasers, as does a decent mid range GPU, and a 550w to 650w psu. It still walks all over the latest consoles, and offers more performance than required for a 1080p tv or monitor.
In fact, it has only been recently, that any demand has been made on gamer systems in my opinion. FarCry 4 and Dragons Age Inquisition both require 4 cores, FarCry 4 will not play on a dual core such as the G3258. And AMD's 4 core offerings are less capable than i5.
Which is why buying a Z97 with 8gb of memory makes so much sense right now for anyone contemplating upgrades on old hardware with new second hand old hardware.