GPU, Rad & chipset questions

[dpends]

Hello,

I'm in the process of putting together my first custom water cooling build and am trying to figure out a couple of points. My current system is as follows:

i5 2500k overclocked @ 4.6ghz - 1.398v
MSI z68A-GD65 MB
HIS 1GB Radeon HD 6870
Antec Kuhler 620 in push/pull config
Case - Corsair 650d (besides CPU cooler 2x 200mm fans)
2 64gb SSDs
2 HDDs
8GB 1866 Ram (2x4)

The system does ok in terms of controlling temps - on Prime 95 tops out a little less than 70C on the CPU

However, I'm concerned about the non-cpu temps, namely the GPU and the nb/sb combo on the chipset. ATI's utility says the GPU idles about 50C, but under stress can get above 80C or even higher. Speedfan shows one MB temp reading as idling at around 65C - I am pretty sure this is the NB/SB - even at idle the heatsink on the chip is uncomfortable to the touch. I imagine under load it must be too hot.

I have picked up a MCP350 and XSPC dual 5.25 bay res made for the pump. I'm trying to figure out the rest of my system. My end goal is to lower temps on the GPU and NB/SB while maintaining the current overclock on the CPU and keeping the system as quiet as possible. I've read through the posted/linked stickies and I still have the following questions:

1) Is a slim profile 2x140mm radiator sufficient for cooling the CPU, GPU and NB/SB? Opinions seem to differ on this. I'd use quiet (~800 to 1000 rpm) fans. Was thinking the magicool slim profile, but am open to other suggestions. I am thinking about adding a 120 rear rad also, but prefer to keep the setup a clean as possible.

2) Is there any real difference in performance between existing 6870 blocks (I see EK, Koolance, and Heatkiller each have blocks - can't find any other 6870 specific blocks). There don't seem to be any reviews that are useful.

3) Is there a good waterblock for the NB/SB chip on a z68?

Thanks for your help.

 

[saint19]

Hi and welcome to Tom's forum.

1- Not, you need a 360 radiator plus a 120 radiator or two 240 radiators
2- Not really, but EK is the most used
3- I can't find any one, but you won't get any big difference with the stock cooling and H20 on your NB/SB.

 

[rubix_1011]

Yeah, saint19 is correct, but OP posted using a 2x140 rad, which...you could get by cooling both of those at stock speeds, but maybe not with low speed fans. So, adding a 120 to the 2x140...you would be ok, but I wouldn't really overclock

Remember, 'slim' rads perform less than normal rads.

No need to watercool NB unless you are going to be doing some pretty heavy overclocking. No need to watercool SB at all.

 

[dpends]

Thanks for your responses.

I think I'll try a 2x140 and a 1x120. I could always add another 2x140 or 2x120 to the front of the 650d, but that involves some difficult positioning of the HDD cages. I'll try keeping the 4.6 overclock on the CPU, and I haven't overclocked (and don't really intend to) the GPU.

On the z68, the NB and SB are combined in a single chip I believe, thus why I was referring to both. It really does get hot, to the point that it almost burns my fingers when touching it at idle.

 

[bejabbers]

you can fit a 200mm phobya rad on the front of the 650D, in the same way I mounted it into my 600t. that would give you the extra rad space to need to keep everything icy cold.

 

[photonboy]

CPU overclock:
Overclocking your CPU with only an HD6870 would make absolutely no difference for playing video games. In fact, CPU usage would only be about 25%.

I personally only temporarily overclock my CPU if I have a lot of videos to convert then I set things back to stock settings.

Overclocking your CPU adds heat and noise, even in idle mode.

Water cooling:
There's really no need for water cooling. I have a very similar setup. I use a Noctua NH-D14 CPU heatsink.

Here's the basic layout I have:
1) two, very quiet, non-variable speed 120mm case fans (one bottom-front, one top-rear)
2) Noctua CPU heatsink
3) graphics card fan (automatic)
4) Power Supply fan (automatic)

My system is very quiet. The HD5870 graphics card is the main noise and that's not even that noisy.

 

[saint19]

Hello,

HIS 1GB Radeon HD 6870

CPU overclock:
Overclocking your CPU with only an HD6870 would make absolutely no difference for playing video games. In fact, CPU usage would only be about 25%.

My system is very quiet. The HD5870 graphics card is the main noise and that's not even that noisy.

Not the same.