My PS3 is modified like that so I can tell the difference. Current one is OFW, but I used that case/cover on my latest CFW slim. Difference in my case was 8-12c on both Cell, and RSX. Yes, is really noticeable change. Now I have that case on CECH-200X, but my CFW PS3 was 210X so you can feel change even on 45/40nm components. You will see that when you put hand at the back of PS3 that airflow is really much better than before.Hi friends, I would like to ask you what you think about making holes to the ps3 Slim on the top where the fan is. Is it good, is it bad or does it not work to improve the temperature?
It's a tricky question actually & I am not entirely sure it's such a good idea to drill holes blindly... Keep in mind that any console cooling system is designed to use a particular air flow with certain characteristics.Hi friends, I would like to ask you what you think about making holes to the ps3 Slim on the top where the fan is. Is it good, is it bad or does it not work to improve the temperature?

the battery get's hotter though.
A hole like that is only going to cool the cpu/rsx better due to not pulling as much air over the other components due to the loss of pressure and making things that you can't measure run hotter.
Could be like an accelero cooler on a video card. Focused purely on the gpu itself, which drops the core temps massively (which is about all people look at), but usually cooks the VRMs and other components well beyond specs (100'C+ in some circumstances in my testing) due to the change in airflow and can cause more problems in the long term than it's really worth.
Battery?
One noticeable differences from factory setup is lack cooling for hdd, not a big deal when 5400rpm is used. But can be problem with 7200rpm. For sure mod like that is also bad for southbridge cooling. Wifi/bt bga can get higher temps, but last one is theory as power supply will be cooler so components under it will get small profit.
But I still decided to make mod in my PS3, as three hottest components are cooled much better. CPU/GPU/Power supply get better cooling. You just need to calculate risk by yourself. I decided that 3 components that have most failure frequency will get better cooling, taking the other risks. Also if you are on CFW you can partially measure how that mod will work on your PS3. Just remove top cover, and try.
Like you can see, there is no simple answer. As a CFW user you can luckily do some measurement before doing mod.
Most problematic in Accelero was that nobody used that small additional radiators, of course I'm talking about active cooling, in passive mode it was simply killer.
But I still decided to make mod in my PS3
Sure, but in current state is looking little bit different than before, because i removed net 2 months ago when mounted mod to new PS3. Still to lazy to place it againCan I see a picture of your ps3 mod?
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As to calling the CPU/GPU the most important parts that need cooled, that's just not true. If any component suffers from even slight overheating, even a small cap, then the ps3 suffers. The day that component dies, good luck finding it & replacing it!
Generally speaking, to burn a ceramic cap, you would need temps well above 100C so I agree it's unlikely here, however burning the cap is not the only thing to worry about, with high variations of temps, components such as ceramic caps can give you all sorts of weird issues like buzzing, ringing, piezo effect & of course varying output!C'mon man you have active cooling systems on capacitors in TV, Radio, Hi-fi, DVD player? For sure this can overburn SB, but capacitors? PS3 don't use some magic parts like that, is standard capacitor like in your TV, and other RTV. Also keep in mind that using that mod is not completely removing other cooling "tunel". Air is still taken in small parts from other holes. I checked that with burning match.