Replacing the Alpha PAL8045?

[Ian]

I currently run an overclocked DLT3C 1700+ in a Chieftec case, Alpha PAL8045 heatsink with a Elanvital 8cm fan (link). According to specs, it's a 44CFM at 31dBA.

Since I'll be getting an AXP-M soon and summer is approaching, I'm considering to invest in some new cooling gears, probably a new HSF for my CPU. Is it worth it upgrade from PAL8045 to a Thermalright? Shall I replace my 8cm fan as well? How much of a difference will it make?

Also, what're the differences between SLK-800U, SLK-900U and SLK-947U? My board has the mounting holes, so they should fit no problem.

Thanks in advance.

 

[archilochus]

SOURCE:: http://overclockers.com/articles373/socketA.asp

HEAT SINK....MODEL....C/W
Thermalright SLK900:. 0.22
Thermalright SP-97:... 0.23
Thermalright SLK800: 0.23
Swiftech MCX462-V:.. 0.26

 

[TheWesson]

I currently run an overclocked DLT3C 1700+ in a Chieftec case, Alpha PAL8045 heatsink with a Elanvital 8cm fan (link). According to specs, it's a 44CFM at 31dBA.

[...]

Shall I replace my 8cm fan as well? How much of a difference will it make?

[...]

Thanks in advance.

I calculate 44 CFM as giving a thermal resistance of (at least) 0.038. 80 CFM = 0.021 ~ so going to 80 CFM would drop your thermal resistance 0.017 C/W ~ your expected benefit would be 1-2C or less for a 100 Watt or less CPU.

I'd say its not worth it if noise bothers you at all.

the wesson

 

[Ian]

So you mean my good old PAL8045 is still up to the job? I thought the new Thermalrights are much better than my Alpha, having read about the great reviews and comments in this forum. I was thinking the Thermalrights will outdo my PAL8045 for a further 3C or 5C.

BTW, do both SLK-947U and SP-97 fit OK on a NF7-S v2.0? On Thermalright's site, they're saying that a neo back-plate is necessary which doesn't come with the package, I'm wondering if anyone has luck with the stock back-plate?

 

[TheWesson]

So you mean my good old PAL8045 is still up to the job? I thought the new Thermalrights are much better than my Alpha, having read about the great reviews and comments in this forum. I was thinking the Thermalrights will outdo my PAL8045 for a further 3C or 5C.

BTW, do both SLK-947U and SP-97 fit OK on a NF7-S v2.0? On Thermalright's site, they're saying that a neo back-plate is necessary which doesn't come with the package, I'm wondering if anyone has luck with the stock back-plate?

I was expressing an opinion about upgrading your fan only.

According to the rankings here an SP or SLK would be a big jump over the Alpha PAL 8045 - 0.34 to 0.25 C/W for an 80-100 watt CPU would be a temp lower on load by 5-10C.

I don't know if your PAL is in the same configuration as the PAL overclockers reviewed. If you've added a more powerful fan then your gain will be less. I think your fan is already more powerful so I would expect a gain of 5C or so.

the wesson

PS just to be clear, don't expect a substantial gain from changing your 40 CFM fan for a more powerful one. Change HS yes, change fan, no.

 

[Ian]

Thanks for you input, TheWesson.

I'll probably replace my PAL8045 then, I'm currently considering either a SLK-947U or SP-97.

Is SP-97 currently the best Socket A heatsink?

According to the reviews here, SLK-947U and SP-97 are neck-to-neck but most people here recommend SP-97, I'm confused. Do both of them work with Abit NF7-S v2.0 w/o the NEO black-plate?

 

[archilochus]

Ian, the neo back plate is a good feature.. www.jab-tech.com has them for $5.00 last I looked...It has a opening in its center, that will allow heat from the back of the socket to escape...Add a mobo wall hole mod. w/ fan, and you have a cool setup.. I plan to get the neo back plate to complete my mobo wall hole mod. The original back plate for my SP-94 HS has a solid plate with a rubber type material in the center. They carry a full line of AS, TIM & TR, HS's there too. A good place to shop..

 

[Ian]

Ian, the neo back plate is a good feature.. www.jab-tech.com has them for $5.00 last I looked...It has a opening in its center, that will allow heat from the back of the socket to escape...Add a mobo wall hole mod. w/ fan, and you have a cool setup.. I plan to get the neo back plate to complete my mobo wall hole mod. The original back plate for my SP-94 HS has a solid plate with a rubber type material in the center. They carry a full line of AS, TIM & TR, HS's there too. A good place to shop..

Unfortunately, I'm in Hong Kong where most online stores don't ship to here and it'll be probably too expensive to have only 1 neo black-plate shipped.

I think I'm getting my new heatsink these few days but before that, I'd like to make sure that either SLK-947U or SP-97 will fit Abit NF7-S WITHOUT the neo black-plate, anyone has an idea?

If the neo black-plate really makes a difference, I can actually ask my cousin to get one for me when he'll be visiting US in the coming weeks, but for now, I'll just have to stick with the stock black-plate.

 

[archilochus]

If I'm not mistaken one of the mobos standoffs interfers with the back plate..A simple cut with a hacksaw is what I heard is the fix..The cut is made to the back plate.."V" cut..

 

[equalizr]

I will never get rid of my 8045. It continues to do a great job with my AXP 2500+ mobile @185x14

Think i might have to update my sig

 

[HiProfile]

I too have a PAL8045 - won it through this forum's F@H contest

I was looking at the heatsink charts today (read the 8055 story), and noticed things are a bit skewed. Not intentionally, of course, but misleading in a way.

The Thermalright HSF's all used an 80x38mm 88cfm fan (5500rpm), while the PAL8045 was only tested with a 3800rpm ~35cfm fan (give or take a few cfm). I know the MIN C/W of a heatsink can't change, but various fans affect what you really get. I won't deny that the thermalrights do very well, but, in my opinion, they aren't incredibly better than the Alphas. I think it was ~.26 for the SLK900 with a ~60cfm 80mm fan, and the PAL8045 at .32 with a 35cfm fan. Based on the various fan speeds they show, I'm guessing it would drop close to SLK900 numbers if they used the same fans.

In short, I don't think it's worth it for you to upgrade to a Thermalright - only do so if you have stability problems. About what TheWesson would be true IF they used the same fans. Another thing to point out is one used an estimated 69 watt load, and the other used a simulated load. IMO get a better fan, and put it on a rheo if you want some silence.

 

[TheWesson]

35 CFM = 0.048 C/W
88 CFM = 0.019 C/W

So roughly speaking the fan difference would account for about 0.03 C/W of the difference.

Looking at the simulated die tests, which are hopefully comparable, 0.32 (Alpha) to 0.23 C/W (SP97) is 0.09 C/W difference.

So the true difference (discounting fan) is ~ 0.06 C/W. So I expect the switch in heatsinks (while keeping fan) to bring about a drop of est. 4.8C (call it 5C) for an 80W CPU (on load).

the wesson