Originally Posted by chrisjames61
Program or programs? Then why aren't we still using one and two core cpu's anymore? The 8320 and 6300 etc..... all shine when you have many open programs, multiple web browsers, watching videos, rendering, listening to music, compiling, all concurrently. Which I do on a consistent basis. They are almost impossible to choke. Try doing that with an i3 or Pentium. There is no denying that for most consumer workloads an i5 is a better cpu than an 8350. But you pay for that luxury.
Because if you run 2 apps that take advantage of 4 cores on an 8 core CPU, both can be comfortable. And It's cheaper to add more cores rather than create faster cores, especially for AMD.
But all threads are not created equal, and threads rely on other threads down the chain, and must wait on each other. This may be only happening in nanoseconds, but the system ends up waiting thousands of times a second or more so it adds up over time. Even when your system says 100% usage, it's not actually true. Even for programs that can take advantage of 8 cores, only certain functions might utilize the full amount of cores. On top of that, AMD's module design makes each CPU in a module wait on each other for FPU access, which slows and cripples integer calculation speed. That's basically an idle on top of an idle on top of an idle...and that's not even including overheads.
Why do you think AMD went with the module design for the FX series? The design changes in FX all scream cost saving measures. That's why you have 1 FPU per every 2 cores. That's why the energy usage is through the roof. The first one was a production cost saving measure, the latter is an R&D cost saving measure. Only those cost saving measures aren't passed on to you, they're primarily passed on to AMD share holders.
The issue with the FX design, is it's really not good at any one task that it's supposed to be because of failings in its design.
For example, let's talk about a work load of many lite programs.
Just general stuff like browsers and photoshop open at the same time. Well tell me......are you going to be editing a photo, while watching a movie, while also browsing the web at the same time? For that matter, say you have 40 tabs open.....are you going to be also looking at all of those simultaneously too? The answer is a big fat NO.
See, when we're not using programs, they're just idling in memory not really taking up CPU. So it relies more on memory capacity for being able to run many programs at once, rather than more cores, because you can only interface with your computer so fast. Even when you have all those programs open, you're getting a lot of idle time in there and low CPU usage overall. Even a dual-quad core with 8GB of memory and just a SATA II SSD can basically make everything seamless under that work load scenario.
Now let's talk about heavy programs. Things like Rendering and video encoding and such.
FPU's tasks are crucial for most heavy workloads. like rendering. With only 1FPU+2cores rather than the traditional 1FPU+1core, you lose a lot of performance. Let's say your workload wouldn't even utilize all the FPU's in an 8 core CPU with 8 FPU's. Well guess what,,,,things are still getting done faster since it spend less time waiting on the FPU. In this case, not utilizing all of an FPU is a good thing because things are getting done on a smaller timescale.
As for video encoding, that is actually done a heck of a lot faster on a GPU. Even a 5 year old video card can transcode video faster than any CPU.
People who need to perform these types of heavy tasks, will find better performance elsewhere that will offer many more options.
And any savings over Intel are wiped out entirely by the extra power usage over its lifetime. Not to mention the FX 8x requires a good board, which doesn't really come cheap. Socket 1150, you can get SATA3 for $40. You won't touch a SATA3 AM3+ board for less than ~$80, and the only really decent boards are more in the $100+ range, with a limited number of brands to choose from. And the extra power usage can add at least $20-$40 cost in a PSU requirement too.
4 threaded applications can only ever use 50% of your PC's full power, and less threaded ones can only use even less.
After all is said and done, you might only really be getting a quad core worth of performance on average, out of an 8 core CPU.