Reapply thermal paste b/c CPU swap? (computer never turned on)

[sethbattery]

So, me being an idiot purchased an i5-8400 and mounted it with its stock heatsink on an ASUS B250. Long story short I now have a B350 in the mail and am wondering if when I move the CPU to its new board if I will need to reapply the thermal paste, keeping in mind the fact that the computer has not been started up in its current configuration.
Thanks.

 

[ss202sl]

Yes. Every time you install the heatsink, the thermal paste will have to be re-applied if it's removed.

 

[volkgren]

You could probably get away with it because it's a locked i5, but it would be best to reapply fresh thermal paste. It's not that expensive and it's always good to have some extra on hand.

Arctic Silver 5 is cheap and would be good enough. https://www.amazon.com/Arctic-Silver-AS5-3-5G-Thermal-Paste/dp/B0087X728K/ref=sr_1_3?ie=UTF8&qid=1529104501&sr=8-3&keywords=arctic+silver+5

Actually just saw NT-H1 is basically same price, a little better. https://www.amazon.com/Noctua-NT-H1-Thermal-Compound-Retail/dp/B002CQU14A/ref=sr_1_1?s=industrial&ie=UTF8&qid=1529104518&sr=1-1&keywords=nh-t1

Woops, the best is MX-4 and it's even cheaper. https://www.amazon.com/ARCTIC-MX-4-Compound-Performance-Interface/dp/B0045JCFLY/ref=sr_1_5_sspa?s=industrial&ie=UTF8&qid=1529104550&sr=8-5-spons&keywords=mx5+thermal+paste&psc=1

 

[sethbattery]

You could probably get away with it because it's a locked i5, but it would be best to reapply fresh thermal paste. It's not that expensive and it's always good to have some extra on hand.

Arctic Silver 5 is cheap and would be good enough. https://www.amazon.com/Arctic-Silver-AS5-3-5G-Thermal-Paste/dp/B0087X728K/ref=sr_1_3?ie=UTF8&qid=1529104501&sr=8-3&keywords=arctic+silver+5

Actually just saw NT-H1 is basically same price, a little better. https://www.amazon.com/Noctua-NT-H1-Thermal-Compound-Retail/dp/B002CQU14A/ref=sr_1_1?s=industrial&ie=UTF8&qid=1529104518&sr=1-1&keywords=nh-t1

Woops, the best is MX-4 and it's even cheaper. https://www.amazon.com/ARCTIC-MX-4-Compound-Performance-Interface/dp/B0045JCFLY/ref=sr_1_5_sspa?s=industrial&ie=UTF8&qid=1529104550&sr=8-5-spons&keywords=mx5+thermal+paste&psc=1

Unfortunately, I live in small rural town an, therefore, Amazon will not ship me thermal paste so it would be a good 2-3 weeks before I can drive the 2.5 hrs to the nearest large city where I can purchase some thermal paste.

 

[volkgren]

You could probably get away with it because it's a locked i5, but it would be best to reapply fresh thermal paste. It's not that expensive and it's always good to have some extra on hand.

Arctic Silver 5 is cheap and would be good enough. https://www.amazon.com/Arctic-Silver-AS5-3-5G-Thermal-Paste/dp/B0087X728K/ref=sr_1_3?ie=UTF8&qid=1529104501&sr=8-3&keywords=arctic+silver+5

Actually just saw NT-H1 is basically same price, a little better. https://www.amazon.com/Noctua-NT-H1-Thermal-Compound-Retail/dp/B002CQU14A/ref=sr_1_1?s=industrial&ie=UTF8&qid=1529104518&sr=1-1&keywords=nh-t1

Woops, the best is MX-4 and it's even cheaper. https://www.amazon.com/ARCTIC-MX-4-Compound-Performance-Interface/dp/B0045JCFLY/ref=sr_1_5_sspa?s=industrial&ie=UTF8&qid=1529104550&sr=8-5-spons&keywords=mx5+thermal+paste&psc=1

Unfortunately, I live in small rural town an, therefore, Amazon will not ship me thermal paste so it would be a good 2-3 weeks before I can drive the 2.5 hrs to the nearest large city where I can purchase some thermal paste.

Well like I said you can probably get by for a short period. But I would plan to replace it.

*I would leave the paste on both the CPU and cooler when you swap motherboards just to ensure you have enough.

 

[boju]

Cooling won't as efficient due to air pockets forming as the paste is disturbed albeit you'll get away with it just fine.

 

[gingerrankin]

So, me being an idiot purchased an i5-8400 and mounted it with its stock heatsink on an ASUS B250. Long story short I now have a B350 in the mail and am wondering if when I move the CPU to its new board if I will need to reapply the thermal paste, keeping in mind the fact that the computer has not been started up in its current configuration.
Thanks.

First a warning: I5-8400 needs a mobo Z370 or B360 or H370 or H310. The B350 mobo is for AMD Ryzen.
If the thermal paste is still wet and flexible, you can use it. If it is dry you should change it because it would not make a good contact.

 

[boju]

Woops good catch. Hope 350 was typo and meant 360.

 

[volkgren]

Oh wow. :/