CM Hyper Evo 212 to budget AIO liquid cooler worth the upgrade?

If you think your only clock speed limitation is due to temp, then yes, it would be worthwhile IMO. Have you experimented (in spite of core temps) to see if the FX-6300 will be stable at higher clocks? What are you using to record temps? Those Bulldozer/Piledriver CPUs were difficult to read accurate core temps with anything other than AMD Overdrive.
Have you seen any throttling at 4.4GHz?

No. The maximum difference when you OC may be an extra 0.2Ghz. Which you’d never notice. Save the money for your next build.

In my opinion the major benefit are environmentals: that EVO 212 fan will be a lot noiser keeping an overclocked 6300 at the same temperature when it's working hard vs. an ML-240 AIO with the right fan profile dialed in. And those RGB lights will definitely provide so much awesome frag-harder goodness you'll wonder how you could have managed before.

It wouldn't hurt to try better case cooling depending on what you have now, along with (maybe more importantly) adding a 2nd fan to the 212 EVO. I used a push-pull 212 EVO for awhile on my FX-8350 (4.7GHz) in a well ventilated case and noticed a lower core temp (higher Thermal margin). It wasn't major, but allowed me to get tp 4.7GHz. I had the exhaust fan facing the rear case fan for added exhausting of the cooler's heat.

The lowly 212 EVO ran much quieter with the 2nd fan for some reason as well. maybe because the fans didn't have to run as fast for the same cooling effect.

hmmm...one case fan only...

Does your case have provisions for mounting a 240mm radiator?

In my opinion you should have 2 fans up front and one on the back. I would use any side fans as intake to feed the GFX card more air but I prefer not to interrupt the front to back airflow.

Will it help dramatically? One way to find out. Most likely it won't.

There's no way I would change from my 212 Evo to a budget AIO cooler. From the 212 to a Noctua D15 or a Kraken X62 or a Bequiet Dark Rock Pro 3? Yes.

There aren't many AIOs that I consider well-made, but there are some.

The Cooler Master MasterLiquid ML240R actually does really well for a 240 AIO. NZXT makes some good products, but I don't like how CAM spies on you.

I could go on and on all day about coolers - I do the large cooler reviews for Tom's.

First keep in mind that Prime95 puts an un-realistic stress load on the processor, it is commonly called a 'power virus'. You should open the case and put all fans on max speed when running a test with it anyway.

Second: a lot of fans are good but how you deploy them is even more important. Remember: cool air comes in front/bottom, hot air exhausted from the rear/top so orient fans accordingly. Side fans supposedly provide cool air for your GPU but any time I've ever used one I found it disrupted airflow through the case such that processor temperature went higher. I find it better to leave the side fan vents open so that cool air is drawn in with the flow up to the rear/top exhaust fans. Just be careful what you do there as I imagine a lot depends on case design and exact location of the GPU.

Much of this really depends on how skillful you are in overclocking and the voltage necessary to maintain stability. However, I actually mentioned the ML240R, not the ML240L. I've tested both, but would only consider the ML240R and really only if I had to choose and someone would lose a life if I didn't pick one of the two. There are very few AIO's I would even consider using, personally....and I have a room full of them.

ML240L, eh.

ML240R, yes.

Although, you're trying to make a comparison against a $30, 7 year old heatpipe cooler and a $120 AIO that focuses more on RGB lighting design than performance cooling. There isn't a magic bullet for what you seek - you are either going to need to spend more money for more TDP watts dissipated, or go cheap and live with something else.

I believe you'd see a marked improvement in CPU temp if you replace the Hyper 212 with an ML240 cooler. This is based on what what you have said about your case design, the single case fan you have installed at the moment and how CPU temp drops when you open the case side panel.

It assumes you install the ML240 radiator in the front of your case with its fans drawing in the cool(er) environment air across the radiator. Further, it also assumes you ensure the case fan at rear/top is oriented to aid in exhausting the warm air from the case back to the environment and that it has sufficient air flow to properly scavenge the case.

This does not mean you wouldn't also see an improvement just from installing two fans in the front and similarly ensuring the rear/top fan is oriented to exhaust the air. But which would provide best cooling to the processor is hard to say.

No you cant replace the liquid or pump, they're sealed units,when an aio reaches the end of its life it's just a binnabble component.

Your temps are down to lack of intake fans plain & simple, a 6300 at that voltage is not hard to keep cool at all.

Liquid cooling coolant should never 'just dry up' - this is an indication of a leak or other malfunction.

It is rather interesting that people assume that AIO's carry the same level of engineering, performance and longevity as high end watercooling components.

If you stop and think about sheer cost alone:

Complete boxed AIO cooler (fans, pump/block, radiator, tubing, coolant): $75-$150

Custom watercooling:
pump: $75-$125
fittings: $5-$12 each
tubing: $1.50-$3 per linear foot
CPU block: $65-$125
radiator: $45-$100
fans: $8-$15 each
coolant: $1 (distilled water) to $20+

I think it's fair to say that debate rages. I do note that even high-end custom loops require maintenance...sometimes frequent...and so would require a means to re-enter the loop if they didn't have one inherent in the design. These AIO's don't usually have more than rudimentary means to service them, at best. That's why I wouldn't invest in a high-end AIO...I have the ML240 model on my over-clocked Ryzen 8 core. No hard-fragging RGB goodness, just a lone little single white back-lit Cooler Master logo on the pump/waterblock assy.

One thing older AIO's suffered from was the rubber tubing used allowed the liquid to evaporate; modern ones use different material that's both less prone to breakage and doesn't allow evaporation. At least so we're told...only way to know is see how it holds up in use. Frankly, I'm more worried about contamination forming in the loop that clogs the ultra-fine cooling fins on the block. These MasterLiquid systems are sealed, no way to easily open them other than cut the tubing or disassembling the block. Again, that's why i keep it cheap.

There is certainly an advantage to 'big air' coolers: they don't suffer any of these problems and also don't heat saturate the way liquid coolers do under sustained heavy thermal loads (even CLC's can, especially if they use a low capacity reservoir). But they require well-designed, usually much larger, well ventilated case and (sometimes a lot) expensive low-noise fans carefully balanced in air flow in order to keep things cool AND quiet. Otherwise you'll just be recirculating the hot air created by the GPU AND CPU inside the case and get nowhere fast. I don't have such a case and don't really want one anyway. There are also a ton of bad ones out there that look impressive and good ones, really good ones like Noctua's, that are generally MORE expensive than the base model ML240.

BTW: I consider ML240R to really be a programmable RGB light show with a 240mm AIO attached so you can't compare price alone for a CPU cooling solution. It's always a compromise, just read up and make your choice.