Choosing the right hardware

[DefLeppard]

I am contemplating on which server hardware to choose for my new Vici cluster. I would like each dialer to be able to handle 250 calls or more with AMD and full call recording. I am stuck between the following two configurations. Please share your inputs as to which of the two would give me the best performance. FYI, I plan to have nightly off-site backup so disk space is not a concern.

Option 1:
Intel i7-4790K 4GHz with 32GB RAM and 240GB SSD

Option 2:
Intel Xeon E3-1231 3.4GHz with 16GB RAM and 2TB SATA drive

[williamconley]

Leave off the model number (i7/Xeon) and instead include the total core count. Core Count X CPU Speed in Ghz = Power.

Also worthy of note: 6G/sec sustained for the SSD? SAS drives can sustain 6G/sec fairly well. But many SATA drives are only 3G/sec and some SSDs can not sustain 6G for very long (from what I recall doing research, we've never had an issue ... but we use SAS for our "needs to be fast" machines).

Lots of memory is always good. But large SATA drives are only useful for storage, not for Dialer and definitely not good for DB.

[DefLeppard]

Both processors have 4 cores and 8 threads (hyperthreading). I am mainly concerned about the dialer performance. The SSD in this case is at least 3 times as fast as compared to SATA based on my tests but how much would it matter on an Asterisk machine? What configuration would give me the highest number of calls without compromising on quality?

Most of my current servers have dual quad core xeons which perform great. I have never tried a single quad core cpu before for high volume of calls. Does Asterisk use all cores and threads of the cpu effectively? I remember long time back there was an argument on the forums claiming that Asterisk is able to use just one core at a time, is this true or still true?

[williamconley]

Both processors have 4 cores and 8 threads (hyperthreading). I am mainly concerned about the dialer performance. The SSD in this case is at least 3 times as fast as compared to SATA based on my tests but how much would it matter on an Asterisk machine? What configuration would give me the highest number of calls without compromising on quality?

Better HD speed always helps. More helpful on MySQL, but still also helpful on asterisk. Recordings have to land on the HD at some point, along with log files if you're writing them.

Most of my current servers have dual quad core xeons which perform great. I have never tried a single quad core cpu before for high volume of calls. Does Asterisk use all cores and threads of the cpu effectively? I remember long time back there was an argument on the forums claiming that Asterisk is able to use just one core at a time, is this true or still true?

All processes can use all the threads, but each individual process sticks to a single thread. So multi-core is much better than single core. Four is good, eight is better, 24 is marvelous but expensive. And do note that under heavy load, hyperthreading could backfire. Be sure you test your configuration under seriously heavy load with hyperthreading on and off to see which one gets you farther before breakdown. We've found that hyperthreading is marvelous under windows but can be counterproductive in linux. Test for yourself. Note of course that you'll likely not be able to "stop and test" when you actually hit that heavy load for real.

[DefLeppard]

Thanks for your inputs williamconley. What cpu is better? The 4GHz i7 or the 3.4GHz E3?

[williamconley]

"Better"? I hope you mean "Faster". Which would be the faster one. Better is subjective, and for that you may want to check the front side bus speed, memory speed, maximum memory capacity ... etc.

However, as a rule ... Faster is Better for CPU. Thus Comparing 4Ghz to 3.4Ghz is fairly obvious.

Next up, as an "exception to prove the rule", you have to beware of the "too new for drivers to exist" concept. Never purchase something you can't take back unless it's been on the street long enough for Linux drivers to exist. Bleeding edge hardware + Linux often leads to disappointment. LOL