Furmark's CPU Burner is not a stability test. It is designed to just load the CPU as much as possible to generate as much heat. That is why it is called a burner and not a stability test. It, AFAIK, has no error detection like a proper stability test.
This is also why you are seeing odd behavior. The pauses aren't because your CPU is unstable, it is because your CPU is loaded to the point it can't handle doing anything else and gets backed up.
It definitely is a good thing to test CPU overclocks with a few different programs, IMO. Because while a CPU might be stable in one program, it might actually be unstable in another. I've seen this several times. Just the fact different programs use different instructions sets can reveal instability in the CPU. For example, old versions of Prime95(always make sure you have the latest) didn't use the AVX instructions. However, Intel Burn Test did use AVX, so Intel Burn Test would often find instability when Prime95 would not. This is because using the AVX instructions not only generate more heat, but they also put more stress on the CPU and tend to reveal instability more. This is actually why a lot of modern motherboards have an AVX offset setting now, that automatically lowers the CPU OC Speed a few notches when AVX workloads are detected.
If you want to test your CPU overclock with a few other stability tests I recommend the following:
Aida64 - You can just use the Trial Version. Under the Tools there is a System Stability test. I run the CPU, FPU, and Cache stress test for at least 12 hours before I consider the CPU Stable. The memory stress test is good too if you are overclocking your memory.
x264 Stability Test - It is best to run this test from a HDD you have in the system if possible, because it does write a lot to the disk. For a quick test I like to use a 10 loop run. But for my final stability test I set it to infinity and then let it run for at least 12 hours. Of course, quick is a relative term depending on your CPU. Because this program is actually doing video encodes, the amount of time it takes to complete a loop greatly depends on your CPU. So for dual-cores I tend to use 4 or 5 loops as a quick test instead or 10.
OCCT - This one has two CPU stability tests in it. One they developed(though I think it is pretty much Prime95 based) and a Linpack stress test. Again, I run both for 12 hours each.
IntelBurnTest - This is another Linpack stress test like the one in OCCT, so I don't really even use this anymore. I just use the one in OCCT. But it isn't a bad one to have if you want to use it.
I really only stability test with Aida64, x264 Stability Test, and OCCT anymore. IMO, that gives a very good coverage on CPU use cases. I don't use Prime95 anymore because the OCCT stress test seems to be extremely similar to it, so it would just be a redundant test. The same goes for IntelBurnTest, the Linpack test in OCCT does basically the same testing so I don't bother running both. Yes, I do run each test for 12 hours after I finalize my overclock, for a total of 2 days(more like 2 and a half actual due to gaps between running tests), but that is what I like to do to give me the best chance of a long lasting stable overclock. I don't like to mess around with finding out my overclock isn't actually stable a few months down the road when I decide I want to do something different that just gaming like encode video. So I just cover all the bases when I set up the overclock so I worry less. I know this much stability testing is not for everyone, and some will say any amount of stability testing is a waste and you should just play games and hope they don't crash, but that isn't what I like to do.
