AMD FX 9590 Overclock,what is the best system for CPU?

that thing is overclocked to the max. good luck overclocking it. if he doesn't have it yet, DON'T GO FOR THE FX 9590. go for an i5 4690k. that will beat it.

Edited for language. Watch it.

Comparing the H100I or any closed loop coolers to a custom cooler, is like comparing a dog to a wet dog in heat. Nasty to even do so.
But more over a custom water cooler is the way to go with just about anything from the i7 1150, 2011, 2011v3 and the AMD 9500 series cpu.
Putting a locsed loop on those sockets is the best way to go.
Simple fact is that some of the mother boards you can get a unit that will cool the boards chip sets and mosfits, plus you can cool the GPUs and memory to even give you a better cooling set up .

the closed loop system`s. are pretty much for lower end cpus, and to make your inside case look some what cool.
It really dont help much with heat. dont get me wrong it does to a point, you might get a temp drop of 1 - 4 deg, with em. if they have good fans on them.

as for a custom water cooling set up, cooling the mother board, cpu, gpu`s and the memory.
you will see a difference in just the temps all around.

you dont need to spend XXXX amount of bucks to get the right set up, start out with a dual rad, cpu block, and build from there. just make sure that when you build your base set up, you get some quick connects, this way you can disconnect lines with out having to drain the unit in hole, or if you feel like you dont want to go that way, then just take your time in draining the unit. start with the cpu block, take it out then tip your PC to the side drain the unit and start from there, with the add on to the set up, dont disconnect the lines from the Rad. if you do remove your rad and cpu block. as one unit. then drain from there. it will safe you insides of the pc from what could be possible damage. then add on from there, add another rad unit and add say mother board block, the gpus dont need much cooling, but only if you are going to over clock, then you can cool the gpus, the main thing that has more heat then anything is the CPU and mother board. the chips on the board dont have fans blowing right on them. so keeping that in mind, cpu block, then mother board blocks. then you can go to gpu`s, hard drivers or ???

when you first go to pick what you want, start with Rads, then CPU block, then move to pump and then line. get the high priced things out of the way to start with. then work on the lower end things like lines, fittings and other.

buy one thing or if you can buy two things at a time and build from there. Sure buy the time the next gen of CPUS and boards come out, you will have to up grade again if you chose to. but you will have the base of the set up done, like pump, cpu block, rads line and other. already so the next round of upgrading wont be so pricey . but as far as closed loops go, i my self i am using the Corsair H100i, and if the fans in the case are set on full speed, i can get my cpu temps down to right around 9c on idel and full loading playing black opps two my temps dont go over 52c. so not to bad and yet not to good. but over all, with closed loops and temps, its best to use a high end thermal compound. this way you can get another 2 - 5 deg drop in temps. just make sure that the cooling fans on the closed loop are better then the ones that come with it. look for more of a HIGHER RMP or higher air flow rate then the factory ones that come with the unit . other then that that all you need to look for : faster fans/ air flow rate and better thermal compound . Artic cool is good, and guild is good for closed loop, just dont go with what came on the closed loop . its ok, for lower end ccpus, but for the AMD 9550 series, it SUCKS. those cpus do give you alot of heat. and i mean alot of heat. i think some place round 150Deg - 200 deg F at times.
so thermal paste is a must have and the good stuff. again i am using the corsair H100i and the AMD 9590, not over clocking, i could if i wanted too, but dont need to. with the set up i am using i could get just under 6ghz. buit dont want to push the board or CPU that high just yet. ill wait for another year or after the warranty is out of date, this way if i screw up the CPU i dont have to hear from AMD< your fault. then i will know its my fault . i burned it up and wont be on down time, with emails and phone calls to amd. to try and hope for RMA.

My FX 8350 against other CPU's using the same graphics card, beats EVERY SINGLE I5 4690Kon Firestrike Extreme, well for that matter every single I5 PERIOD and MOST I7's until you get to the I7 4790K. That even includes I5's and I7's that are runnning four way SLI, my three way scores are higher... so, I wouldn't be too sure about the 4690k being so much better... according to user submitted, real world scores on futuremark.com, it's NOT.

Anyway, the Antech cooler is probably enough, I just use an H80i myself. In my own tinkering on my Asus Crosshair V Formula Z and Gigabyte 990FX UD3, both responded to LESS memory more favorably. 16gb seems to be my personal sweet spot, but honestly I've scored even higher scores with 2 unmatched 4GB dimms at only 1333 but a lower CAS. My 16GB is currently just a set of HyperX 1600 CAS10.

I have SEVERAL GTX 760's and have personally found the 2GB version running 3 way SLI to be the fastest. Although my 3 way is a mixed set of 2 ASUS and one EVGA. The 4GB version are EVGA.

I've been toying with the idea of getting a 9590, but have decided to try yet another set of dimms first, and am also currently hunting down a pair of R9 290x cards for CrossFire. If my research is correct, this will probably be the apex, or darn near, what my system could POSSIBLY be capable of.

My guess is your friend isn't having any problem running any games right now at good frame rates as I can run almost any game at 5760x1080 at full high/ultra specs. There are some exceptions of course.

His best performance upgrade is probably going to be what has been mentioned, a GPU upgrade. But it won't be enough to justify the price.