Waterblock design help

[Finners]

Was mulling over the idea of making myself a universal GPU block at work today and am trying to decide which design is best to go for. These are the water channels that will go over the core.

These are very early design ideas I've literally made in the last half an hour. These are all taken in the perspective of a cross section, so imagine the waterblock chopped in half and you are looking the same way the water will flow.

Design 1.

Conventional slots with 0.5mm between heat source and water channels.

I'm limited here with the depth is can go with the channels as its the only tooling I have available

surface area (in contact with water) 3640mm^2

Design 2.

Easier to machine but requires me to have more metal between the heat source and the water channels.

Surface area (in contact with water) 3166.8mm^2

Design 3.

Same as 2 but an extra row of holes. I'm not really limited how many rows I can put in (without being ridiculous) but have to keep the lump of metal at the bottom.

Surface are (in contact with water) 4750.2 mm^2

So what do you think? How much of a difference would I see with there being 2mm instead of 0.5mm between the heat source and the water channels? made of copper of course

Which design do you think would be least restrictive?

Like I said this would just something I started thinking about at work today and though i would ask for opinions.

 

[iO]

I would say 0.5 mm for the base is too thin. The inner tensions of the material would warp the part while milling and you'd get a screwed base.
I'd go for at least 3mm of base thickness as this also increases the thermal capacity and a faster and more even spread of heat transfer.

As for the holes I don't know, I guess there is reason why WB manufacturers stick to the regular fin structure design...

 

[Sasqui]

Most high end waterblocks use and impinge method to get the highest flow over the hottest areas. That said, I was toying with this idea after seeing yours:

 

[Finners]

Never thought about that sasqui, might draw it up when I get the chance and see how big of an improvement there is with surface area.

 

[OneMoar]

surface area is king they use fins because they are easy to machine
the holes idea would work best if the water was made to pass though them
so a inlet on one side and a outlet on the other