XD3 or XD5

[Peter80]

Hello 

I'm just looking for some assistance with my current setup. I recently liquid-cooled my PC with the XD7, EK Water block, and an EK water block for the 6800XT. 360 Rad 40mm thick.  It seems that my 2920x is getting too hot for my liking and hotter than just a 360 AIO I had installed. 

I'm assuming 1x 360 rad is not enough? 

The heat coming off the Radiator seems somewhat excessive when gaming. The 6800XT looks perfectly fine, getting to around 62 degrees or less. The 2920x keeps hitting 60'c plus, which is not crazy over the top, but I was hoping both would be cooler. 

I purchased an XD3 sealed from eBay at a discounted price to use in another build but am reconsidering as I might use the 360 radiator, XD3 for that setup in my current build by removing XD7.

Is the XD3 powerful enough to keep 2920x, 6800XT, 2x 360 40mm radiators cool. I don't mind purchasing the XD5. The XD5 is a cheaper option than a new case with a side Rad option and I can sell the XD7 on eBay.

This is the first time I've done liquid cooling so I'm still learning.

Thanks

Peter

[c-attack]

The XD3 is more than powerful enough.  However, it is a DDC type pump and this is a bit different if you've never had one.  DDC pumps are compact, typically don't use the loop fluid to cool the pump, and are designed to produce a lot of head pressure at low and middle pump speeds.   It is essentially geared like a truck, lots of low end torque but decidedly loud at high RPM.  DDC pumps are popular choices in smaller builds where the D5 mounting style may be difficult or in loops with multiple components where the user does not want to run the pump at high speed.  

 

The XD5 is likely the same pump unit from the XD7, a D5 based pump.  D5 pumps offer greater theoretical flow rate but produce less head pressure at lower speeds.  So at 2000 rpm, a XD3 likely offers better flow than a XD5, but the XD5 will pull ahead as your drift past 3500-4000 rpm, at which point the XD3 will be too loud anyway.  

 

Actual tangible temperature differences are likely to be hard to ascertain in most systems without going to extremes (lots of restriction + low pump speed, minimal restriction + maximum pump speed, etc).  That means most people should choose based on form factor and mounting options.  The XD3 is interesting, but I would warn anyone who is a dedicated noise freak to avoid DDC pumps in general.  It's not what you should use in a system with a passive or "zero noise" type of goal.

[LeDoyen]

And to get to the first question, yea, a single 360 rad is not enough 🙂 Typically, ballpark, you can guesstimate that a 360 will be enough for about 300W worth of TDP. your build is closer to 500, so it's a tad overloaded.

It still functions as you saw, but you get aircooling levels of temperature, and the water must be pretty hot.

two rads, you will see quite a massive improvement, but water flow won't really contribute to it.

Water flow only negatively affects temperatures at very low pump speeds, like under ~30% PWM where the warm water exits the block too slowly.

beyond that, there's usually enough flow to cool the blocks effectively and temperature will drop very little with flow increase. on my build between 50 and 100% PWM i save maybe one °C on the GPU.

So you can use either model of pumps and only consider more practical aspects to base your choice.

I personally prefer DDC for the higher flow at lower speeds, but in small pumps like the XD3, they can be pretty whiny, high pitch which is more noticeable than the low hum of the D5.

Filling your loop with the XD3 is going to take longer too, because of how small the reservoir is. the XD5 will make it easier.

Apart from that, as C said, they will both do the job without problem.

 

 

Nerd side note !

1 hour ago, c-attack said:

The XD5 is likely the same pump unit from the XD7, a D5 based pump.  D5 pumps offer greater theoretical flow rate but produce less head pressure at lower speeds.  So at 2000 rpm, a XD3 likely offers better flow than a XD5, but the XD5 will pull ahead as your drift past 3500-4000 rpm, at which point the XD3 will be too loud anyway.  

 

Actually, i changed the pump on an EK Kinetic flat pump/res (it can use both models), and they both reach the same flow, give or take a few L/h.

the D5 spins 200 rpm faster, but the DDC has more pressure, so in the end they are about identical. But at normal speed the DDC is always on top by 20 - 30L/h, so to reach the same flow as a D5, you can slow it down and make it even quieter. And it doesn't have those couple of noisy ranges like the D5 have.

It was an interesting experiment but without flowmeter, they are hard to compare (and i did stick with the DDC that was, in my case, the quietest 😛 )

[Peter80]

Thanks for the assistance, I installed the XD3 with the second radiator - It's made such a difference in temps.