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Old 09-30-2018, 02:13 PM   #21
ChaosLegionnaire
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Default Re: Your Video Card Cooling Mods - Sapphire Radeon HD4650 1G

well, i'd just like to affirm that your testing methodology is sound on both the 2400 xt and 4650.

with the ambient temp of 29C and the max load temp of 37C, u have a delta or rise above ambient of 37-29=8C. since the 2400 xt has a tdp of 20w and the 4650 having a tdp of around 50w, the heatsink has to handle 2.5x the heat output of the 2400 xt. since the heatsink gave a +8C delta above ambient with a 20w tdp heat load, so with 2.5x higher tdp to handle, we have 8x2.5=20C delta above ambient. with an ambient temp of 29C, so we should be expecting temps of around 29+20=49C on the 4650. in practice, your result was a max load temp of 50C.

so i just love it when theory matches up with practice! this means there are no mounting issues with the heatsink and it works perfectly exactly as it should! the above theoretical calculations and momaka's practical testing methodology above should be useful for anyone looking to measure the tdp of a heatsink and how much heat it can handle and what temps u should be expecting. therefore, this negates any newbie mistakes of using an inappropriate heatsink for a video card and ending up with an even worse overheating video card!

let me tell u all about it. recently, i bought a few video cards off junkbay that came with third party heatsinks. thing is, they all had inappropriate heatsinks for the tdp required. i had a 5870 with arctic twin turbo pro. arctic lists the max tdp handling capacity of the twin turbo pro as 125w and the 5870 has a tdp of around 200w! the video card turned out faulty when i tested it and i had to file for a refund.

then i got another 5870, this one has a zalman vf1000. i put a zalman vf1000 on my 6800 ultra before and it struggled to contain the 75w tdp of the 6800 ultra. i dont need to tell u what happens when u try a 200w heat load on a heatsink that can barely handle 75w! i also found that the plastic washers on the back of the card to insulate the pcb from shorting on the spring loaded screws had melted and fused onto the card's pcb. i wonder how hot the gpu ran to cause the plastic washers to melt like that. over 100C?

then i got an asus 4870 dark knight. the dark knight cooler has 4 heatpipes and its design is almost exactly like the vf1000 except upside down, so its an inverted vf1000. the 4870 has a tdp of 150w. no way that dark knight cooler can handle that when the similarly performing vf1000 struggled with 75w tdp.

i find it mind boggling when ppl try to supposedly "improve" the cooling of their video cards but have no idea what they are doing and make the cooling worse instead than even with the stock cooler! so i hope some grey matter use with mathematics and practical physics above, teaches ppl to use the right cooler for your video card!
Quote:
Originally Posted by momaka View Post
I was getting over 65C on the core (under full load). notice the darkening of the PCB on the back side under the GPU chip? this card came out of a very dusty OEM PC
the 65C u got isnt hot enough to cause the pcb to darken. rather its the most likely cramped oem casing and poorly ventilated oem pc case plus the combined effect of the dust that led to the gpu running even hotter than the 65C u got. i estimate the internal case temps of the gpu running at max load hit over 80C maybe even close to 90C over a prolonged period. thats what caused the pcb to darken.

i highly doubt that gpu will last long. it might need a reflow soon. tho with the 50C load temps now with the new heatsink, the gpu will be lovin' u for givin' it a chill from all the stuffiness it experienced with its previous owner!
Quote:
Originally Posted by momaka View Post
I also had some Shin-Etsu thermal compound that I wasnt sure if it was good or not, as it looked rather hard to spread (thick, but not dry).
i have used shin etsu before and i have both the x23 7783d and g751 pastes and yes they are thick and i had to spread them with a spatula. the reason for that is that it has to be thick enough to iron out all the microscopic air bubbles to improve the heat conductivity or sumthing since air is an insulator, not a conductor of heat. i could be wrong tho on why it has to be thick to be good, so dont quote me on that.

i practice my tim application technique by practicing spreading cold butter on bread with a metal butter knife. kills two birds with one stone... or in this case, feeds two mouths with one toast.
Quote:
Originally Posted by momaka View Post
Ive played around with these small coolers quite a bit, I can tell you from experience that they are not capable of more than 30 Watts TDP max.
well dont toss em just yet. they should do well for cooling the entry level series of each generation from the 2000 to 5000 series all of which have 20-25w tdp. e.g. 2400 pro/xt, 3450/3470, 4350 and 5450. all of em should have 43mm square mounting hole pattern which fit the cooler. in fact, that 4650 stock cooler should work nice in replacing the stock passive heatsink of my 5450. u should sell that 4650 stock cooler to me! lol!

also, if u dont mind and have the time, u should try that 4650 stock cooler on the dell 2400 xt instead. i wonder how it would perform. i theorise it should perform great! not sure what the ambient temp was when u tested the 4650 stock cooler and got that 65C load temp result but i am going to ass-u-me the ambient temp is 29C. therefore, 65-29=36C delta above ambient. since the 2400 xt has 2.5x lower tdp than the 4650, 362.5=14.4C delta above ambient. with an ambient temp of 29C again, we get 14.4+29=43.4C. so u should get around 43C load temps give or take a couple of degrees with that 4650 stock cooler on your dell 2400 xt. well, if u have some spare time, that would be an interesting experiment to try out! give it a go and lemme see the results! thanks! hehehe...
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Old 09-30-2018, 11:55 PM   #22
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Default Re: Your Video Card Cooling Mods

LOL killing low profile cards must be the new thing.
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Old 10-02-2018, 08:13 AM   #23
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Default Re: Your Video Card Cooling Mods

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LOL killing low profile cards must be the new thing.
When manufactures are too lazy and/or too cheap to put a proper heatsink ... yeah, I'll put whatever I have that is better than their crap. I don't have any low-profile PCs, so I frankly couldn't give a crap about low-profile stuff. Besides, if you are stuffing a 50W+ video card in a small shoebox PC, you're doing it wrong. Most small SFF/USFF PCs already run way too hot inside. They don't need more heat. So a mid-range low-profile video card is a silly idea anyways... unless it really has a properly designed heatsink that exhausts all of the heat outside of the case - and those usually don't come in anything less than a dual-slot and full-profile.

Quote:
Originally Posted by ChaosLegionnaire View Post
well, i'd just like to affirm that your testing methodology is sound on both the 2400 xt and 4650.
...
the 65C u got isnt hot enough to cause the pcb to darken. rather its the most likely cramped oem casing and poorly ventilated oem pc case plus the combined effect of the dust that led to the gpu running even hotter than the 65C u got. i estimate the internal case temps of the gpu running at max load hit over 80C maybe even close to 90C over a prolonged period. thats what caused the pcb to darken.
Yes, 65C isn't hot enough for that. But this was the temperature I was reaching only after a few _minutes_ of medium-high load... and at 18C room temperature with _open_ case. Since GPU temperature rises proportionately with ambient case/room air temperature, @ 28C (normal temperature in my computer room for the summer), I expect that stock cooler to easily hit 75C and possibly leveling off around 80-85C or higher with all of the dust it had - which is all hot enough to darken a PCB. (And for the record, I cleaned the stock cooler's fins from dust prior to testing it, so the overheating clearly wasn't from dust accumulation alone).

Meanwhile, this modded cooler keeps the card at around 50C with the same 28C room/case ambient.

I guess as classic car guys like to say: there's no replacement for displacement. In the case of cooling, there's no replacement for surface area (with some airflow, of course).

Quote:
Originally Posted by ChaosLegionnaire View Post
let me tell u all about it. recently, i bought a few video cards off junkbay that came with third party heatsinks. thing is, they all had inappropriate heatsinks for the tdp required. i had a 5870 with arctic twin turbo pro. arctic lists the max tdp handling capacity of the twin turbo pro as 125w and the 5870 has a tdp of around 200w! the video card turned out faulty when i tested it and i had to file for a refund.
Not surprised.

Whenever I'm bored, I browse for cheap video cards on eBay. I've been doing that for a few years now, and I've noted that there are video cards with certain coolers that are almost regularly listed for parts or as broken. I saw a few like my Sapphire above as well, so no doubt the stock HS is poorly matched for it. Other regulars are the single-slotted reference HD4850 cards, single-slotted GeForce 8800/9800 GT (which is over 90% what they come with), and GTX 560/Ti with single fan... that's just to name a few off top of my head. There are many more in this list. Most artifacted cards are due to crappy cooling.

Quote:
Originally Posted by ChaosLegionnaire View Post
i dont need to tell u what happens when u try a 200w heat load on a heatsink that can barely handle 75w! i also found that the plastic washers on the back of the card to insulate the pcb from shorting on the spring loaded screws had melted and fused onto the card's pcb. i wonder how hot the gpu ran to cause the plastic washers to melt like that. over 100C?
Hey, it's a self-reflowing video card! How neat.
The feature doubles as self-drying/baking to remove moisture from air humidity. Awesome!

Quote:
Originally Posted by ChaosLegionnaire View Post
i have used shin etsu before and i have both the x23 7783d and g751 pastes and yes they are thick and i had to spread them with a spatula.
Thick pastes, I don't spread. I find that the heatsink pressure does a better job at that while pushing out all of the air bubbles indeed. But this only works on GPUs and CPUs with exposed dies. Applying thick paste on a CPU/GPU with a large heat spreader tends to yield not great results, IME. So for those, I use a less viscous (runny/watery) compound.

Quote:
Originally Posted by ChaosLegionnaire View Post
well dont toss em just yet. they should do well for cooling the entry level series of each generation from the 2000 to 5000 series all of which have 20-25w tdp. e.g. 2400 pro/xt, 3450/3470, 4350 and 5450. all of em should have 43mm square mounting hole pattern which fit the cooler. in fact, that 4650 stock cooler should work nice in replacing the stock passive heatsink of my 5450. u should sell that 4650 stock cooler to me! lol!

also, if u dont mind and have the time, u should try that 4650 stock cooler on the dell 2400 xt instead. i wonder how it would perform. i theorise it should perform great! not sure what the ambient temp was when u tested the 4650 stock cooler and got that 65C load temp result but i am going to ass-u-me the ambient temp is 29C. therefore, 65-29=36C delta above ambient. since the 2400 xt has 2.5x lower tdp than the 4650, 362.5=14.4C delta above ambient. with an ambient temp of 29C again, we get 14.4+29=43.4C. so u should get around 43C load temps give or take a couple of degrees with that 4650 stock cooler on your dell 2400 xt. well, if u have some spare time, that would be an interesting experiment to try out! give it a go and lemme see the results! thanks! hehehe...
Already ahead of you there

Though I didn't use the Sapphire HD4650's stock cooler in particular, I did reuse a low-profile PowerColor Radeon HD6670 cooler on one of my HD2400 XT cards. I just didn't take pictures of it, as I didn't think it was that interesting of a card/mod, given how saturated the online market is with used HD2400, 3450, and 6450 cards (they are literally sold by the bucket). In any case, the PowerColor HD6670 low-profile stock cooler is about the same size as the HD2400's reference cooler. But it has much more fins and much thicker base, similar to the Sapphire HD4650 (but still quite inadequate for a 60W TDP). So the temperatures were much lower on the HD2400 - actually very very close to what you calculated/estimated. I don't remember exactly, but I think I was getting indeed around 40-43C load with 28C room ambient and closed case. Stock HD2400 HS in that same case with same room temperature was giving around 60-65C under full load. I'll take some pictures when I take it out for replacement maybe this or next month and also make some graphs. But yeah, that one worked quite well.

And for brethin's sake, I didn't kill a low-profile card with that mod.

Last edited by momaka; 10-02-2018 at 08:17 AM..
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Old 10-10-2018, 12:32 PM   #24
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Default Re: Your Video Card Cooling Mods

another candidate up for modding is a sapphire radeon 8500le 64mb. i bid on it on junkbay cuz those gf4 ti cards just have overinflated prices! before the seller shipped the item, he said that while testing the item before shipping out, there was some noise from the fan and that he included a second fan in the package.

when i got it and tried testing it on the abit ic7-g, i found that the fan had partially seized with a dry bearing most likely from the noise it made tho it was still spinning very slowly. i still had my dual 80mm fans blowing at it to keep it cool. i tested it in win98 by forcing the driver to see it as a radeon 9000 series card (because the omega drivers i was using no longer support the 8500 series) and it worked fine in many games i tested it with.

i tried removing the fan to lube and clean the bearing but the stator broke apart while i was trying to remove the rotors. grrr! the screw holes for the spare fan the seller provided dont line up with the original fan. there is no way to remove the heatsink because it seems to have been glued down onto the gpu with thermal epoxy. so the only way is to mod the heatsink to attach a more powerful fan onto it.

after cracking my head and having a headache from it for over a week! i finally had an eureka moment. i decided to use cable ties and to use the stator frame of the original fan as an anchor point to secure the cable ties onto. i had to run two cable ties in a "U" manner under the stator frame and then screwed the stator frame back onto the heatsink with the original screws to secure the cable ties onto the heatsink.

took me a few tries to get it right. then i just ran the cable ties sticking up from the heatsink through the mounting holes of the 40mm fan the seller gave me for free. used one of the mini 2-pin to 3-pin fan adaptors i got off aliexpress to connect the fan to the video card fan header.

i ran some game tests with dx8 games to see how hot it ran and if the mod cools well. i also had the usual 140mm fan blowing air over the pci and agp slot area. measuring the temperature of the rear pcb side of the gpu with the scythe ir thermometer, i got 53-54C while gaming. so this means the gpu core probably runs at around 60C at max gaming load. so i wouldnt say it cools well but this is the best it can do since i cant replace the heatsink as its glued down with thermal epoxy.

so anyone have any ideas for removing and weakening thermal epoxy? does acetone work?
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Old 10-14-2018, 04:59 PM   #25
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Default Re: Your Video Card Cooling Mods

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so anyone have any ideas for removing and weakening thermal epoxy? does acetone work?
No ideas, but I do know temperatures below freezing weaken the epoxy, though. In the past, I've removed the heat spreaders on PS3 GPU chips just with heating the heat spreader to around 60-80C and using brute force to pry it off. But that's always a bit risky.

Anyways, I do have a Radeon 7500 AGP video card with what appears to be the same heatsink as yours (in fact, the whole PCB appears to be very similar to your card with a few minor differences.) And on mine, the fan still works (though it was very noisy and almost stuck when I got it), but I do plan on changing the heatsink on it, just for the sake of having a more quiet card and maybe more reliable too when I use a different fan. I'm thinking to use the same HS as the ASUS V3800M I put in post #2 of this thread.
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