Fully featured time command on Mac OS X?

On some unix systems I've been used to a time command which many options including ways to format the output (-f) and redirect the output to a file (-o), see for example this man entry of time.

However on OS X it seems that we have a crippled down version that only has two (not so useful) options -lp. (I'm on Snow Leopard if that matters.)

So, how can I get a better time for my system?

How to test router-to-PC connection speed?

Is there a way to benchmark how fast my router is connected to my PC, independent of the internet?

I've had slower-than-usual internet-based benchmarks, and I'm having a hard time figuring out if it's because of a bad router-to-PC connection (interference, bad signal, etc.) or if it's indeed because my internet is actually slower.

How can I produce high CPU load on a Linux server?

I’m currently in the process of debugging a Cacti installation and want to create CPU load to debug my CPU utilization graphs.

I tried to simply run cat /dev/zero > /dev/null, which works great but only utilizes 1 core:

Is there a better method of testing/maxing-out system resources under load?

Related: How can I produce high CPU load on Windows?

What do I need to consider when buying hardware to meet my needs?

I'm looking to build a new computer from the ground up. I'm not sure what to look out for and need guidance and help on how to pick the hardware needed to construct my new rig.

How do I know what to buy?

• How do I find out if a given CPU will be enough for a certain game or application that I want to run?

• How do I find out if a given graphics card will be enough for a certain game or application?

• What is important when looking at motherboards?

• How much memory do I need?

• How do I know how much wattage I need for a power supply?

• What size case do I need?

• What relevant standards do I need to read up on and be aware of?

  PCI, PCIe, SATA, USB 2.0, USB 3.0, etc...

• What "gotchas" do I need to be on the lookout for?

Please keep responses generation-agnostic to ensure they will be helpful to our future users.

While Stack Exchange does not permit shopping recommendations, it doesn't provide any general advice to consider when buying hardware. So, instead of just telling those that ask what to buy that it's not allowed, let's tell them how to figure out what they need.

This question was Super User Question of the Week #20
Read the June 20, 2011 blog entry for more details or submit your own Question of the Week.

Is it normal for Windows Software Raid (Mirroring) to slow a drive's performance?

I've been doing some performance tests on a few of my drives lately, trying to figure out which combination of drive/raid-level(or not) will give me the best performance (for Hyper-V incase anyone's curious).

However, I'm seeing some behaviour/results that seems quite odd to me.

I'm using standard Windows Software Raid (ie, not fake motherboard raid, and don't want to spend the few hundreds of dollars I'd need to in order to get a decent hardware raid controller) for these tests. I'm not at all concerned about backups or drive failure (Windows Home Server, FTW!), I'm focussing strictly on performance. These tests are being executed in Windows 7 Ultimate (My server will end up being Server 2k8R2).

I've got two Western Digital Black 640Gb drives (SATA300) which give the following results using Atto Disk Benchmark (I also get similar results with SQLIO):

Drive               Read    Write
640(#1)              120      115
640(#2)              125      110
Mirror (Raid-1)*      82       77
Striped(Raid-0)      162      145

The unexpected result is the drastically poor performance fo the mirrored drives. I was expecting reads to be slightly better than a single drive, not significantly worse..

I've run the tests a number of times (breaking and recreating the array and mixing up the mirror vs striped vs single drive tests) with comparable results.

For anyone using a similar software raid setup, do these numbers jive with what you're working with, or are they completely off base? (Because the certainly seem so to me...)

What does the file /proc/cpuinfo tell me about the hardware?

I rent a server which should have "2 Cores x 2,2 GHz". When in run the command cat /proc/cpuinfo I get the following result:

processor   : 0
vendor_id   : AuthenticAMD
cpu family  : 15
model       : 67
model name  : Dual-Core AMD Opteron(tm) Processor 1218 HE
stepping    : 3
cpu MHz     : 1000.000
cache size  : 1024 KB
physical id : 0
siblings    : 2
core id     : 0
cpu cores   : 2
apicid      : 0
initial apicid  : 0
fdiv_bug    : no
hlt_bug     : no
f00f_bug    : no
coma_bug    : no
fpu     : yes
fpu_exception   : yes
cpuid level : 1
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow extd_apicid pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips    : 2009.48
clflush size    : 64
power management: ts fid vid ttp tm stc

processor   : 1
vendor_id   : AuthenticAMD
cpu family  : 15
model       : 67
model name  : Dual-Core AMD Opteron(tm) Processor 1218 HE
stepping    : 3
cpu MHz     : 1000.000
cache size  : 1024 KB
physical id : 0
siblings    : 2
core id     : 1
cpu cores   : 2
apicid      : 1
initial apicid  : 1
fdiv_bug    : no
hlt_bug     : no
f00f_bug    : no
coma_bug    : no
fpu     : yes
fpu_exception   : yes
cpuid level : 1
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow extd_apicid pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy
bogomips    : 2009.48
clflush size    : 64
power management: ts fid vid ttp tm stc

There it says 2* 1000 MHz. I called my provider and they said that the 2.2 GHz are not shown, but they are installed. How can that be?

Measuring performance before and after upgrade

What is the best free software to measure computer performance? I want to make couple of small upgrades and i'd like to see if they were worth the money/time spent.

Do uninterruptible power supply increase the life expentency of hardware?

Do UPS increase the performance or life expectancy of the hardware connected to it? What if the UPS has a built in line conditioner?

Software to benchmark software installation times [closed]

Is there any software that exists to benchmark how long it takes to install software? I know there are programs to benchmark startup times, but I'd like to measure how long the installation package for a given program takes to run. This will be used in an upcoming Super User Blog post.

How can I compare the quality of different voice products?

I want to know how I can compare the quality of different voice products, in order that it gives the best audio quality rating for calls through the internet in average network conditions.

How exactly can I benchmark this? Are there benchmarks available on the internet?

How to benchmark kernel (-Os vs -O2)

It seems logical to me that on a 64-bit kernel compiling it to optimize for size might help overall. (My distro of choice uses -O2) It has the benefits of more registers and memory and perhaps less cache contention than normal optimized code. I have a kernel compiled like this and it seems excellent. However my question is how can I prove this? I like using Phoronix for "real world" sort of benchmarks so I would prefer to test cases like that. What should I pick to test? Does anyone else have any alternatives? Thank you very much in advance.

Benchmarks relevant for a Visual Studio .NET development workstation

I am developing a system with Windows 7 64-bit, Visual Studio and Sharepoint on a virtual workstation on some kind of VMWare server.

The system is painfully slow, with Visual Studio lagging behind when entering code, IntelliSense lagging, opening and saving files takes ages when compared to a normal budget laptop.

As far as I can see the virtual machine has OK specs and does not seem to be swapping etc., and the IT department also says that they can't see anything wrong when they're monitoring the system.

As long as the problem is not well-documented, the IT department and management does not want to throw money (=upgraded laptops) at us, so I need to show some sort of benchmark.

It has been many years since I did any system benchmarking, and I don't know the current benchmark software, so my question is which benchmark will be most relevant for Visual Studio performance? Not just for compiling fast, but also to reflect the "responsiveness" of the system.

Free tool for WiFi quality assessment

I found this neat and dead-simple DIY project for boosting a WiFi AP's antenna range, and I was wondering how I could actually do a before/after benchmark.

Are there any free tools that could test the quality of a WiFi network? I'm thinking of walking around my appartment with my netbook in hand and eventually end up with a 'coverage map'.

Most searches I tried ended up in some wardriving tool or another - they don't seem to fit for my purpose, but correct me if I'm wrong.

What I'd like the tool to have (a subset is fine, but the more, the better): - show the instantaneous signal strength, and not just with a 1-5 bars resolution as Windows does. I want hard numbers.

• do a throughput test (U/L, D/L). For this, I guess I could use a 2nd computer on the same subnet, wired directly to the AP, and try a large file transfer.

• do a latency check on the local LAN

So, any suggestions?

Makefile fails to install file correctly, installing HPL

I started installing HPL a while ago, and had a related question. I've been following along with this guide from Intel. I figure this warrants a whole new one. When I try to make the archive, the output seems fine until the end, where it gives an error.

make[2]: Entering directory `/hpl-2.0/src/auxil/intel64'
Makefile:47: Make.inc: No such file or directory
make[2]: *** No rule to make target `Make.inc'.  Stop.
make[2]: Leaving directory `/hpl-2.0/src/auxil/intel64'
make[1]: *** [build_src] Error 2
make[1]: Leaving directory `/hpl-2.0'
make: *** [build] Error 2

Going to the directory /hpl-2.0/src/auxil/intel64 shows a file, "Make.inc", but it's highlighted red, and the white text blinks.

Is there a way to manually make that file? What do I need to do to get the makefile to do this for me?

Why the results of Truecrypt and cryptsetup (LUKS) benchmarking are so different?

I want to encrypt a part of my HDD. But before that I wanted to benchmark the different algorithm available wondering if I should choose aes-xts-256 or aes-xts-512.

Note: I don't have aes hardware acceleration. The benchmarks were repeated multiple times without much change. I'd like to state clearly that these benchmark are only valid on my computer (Debian, core 2 duo). This is not intended to be a complete LUKS-TrueCrypt comparison.

TL;DR: go to part 4

1- Cryptsetup

So I downloaded cryptsetup v1.6.0 to make use of the new cryptsetup benchmark command.

Command

$cryptsetup benchmark

Results

 #  Algorithm | Key | Encryption |  Decryption
     aes-cbc   128b   128,2 MiB/s   157,2 MiB/s
 serpent-cbc   128b    49,6 MiB/s    57,7 MiB/s
 twofish-cbc   128b   138,0 MiB/s   183,8 MiB/s
     aes-cbc   256b    97,5 MiB/s   121,9 MiB/s
 serpent-cbc   256b    51,8 MiB/s    57,7 MiB/s
 twofish-cbc   256b   139,0 MiB/s   183,8 MiB/s
     aes-xts   256b   156,4 MiB/s   157,8 MiB/s
 serpent-xts   256b    55,7 MiB/s    58,7 MiB/s
 twofish-xts   256b   161,5 MiB/s   165,9 MiB/s
     aes-xts   512b   120,5 MiB/s   120,9 MiB/s
 serpent-xts   512b    55,7 MiB/s    58,5 MiB/s
 twofish-xts   512b   161,5 MiB/s   165,3 MiB/s

Thoughts

• In cbc mode, serpent is surprisingly fast at decrypting!
• In xts mode, serpent is clearly the fastest.
• The key size seem to have almost no noticable effect on serpent twofish.
• aes does not behave well when the key size is increased.

Updates out of VM

2- TrueCrypt

I was really surprised as aes is known to be the fastest (even without hardware acceleration). So I downloaded TrueCrypt to double-check these results. TrueCrypt uses the xts mode by default so I assume it also use it in its benchmarks.

Method

1. Tools > Benchmark
2. Choose any buffer size (here, 5MB)
3. Click on "Benchmark"

Results

 #  Algorithm | Encryption |  Decryption
         AES     106 MB/s      107 MB/s
     Twofish      78 MB/s       76 MB/s
     Serpent      41 MB/s       42 MB/s

Thoughts

These results corresponds much more to what is expected but do not match well with cryptsetup's results.

3- General thoughts

• cryptsetup provided better general performance than TrueCrypt in this case. This could be explained the following way:
  • cryptsetup was compiled on my system with compiler optimization routines while TrueCrypt was already compiled in a generic way;
  • AFAIK cryptsetup uses kernelspace crypto modules while TrueCrypt uses userspace crypto routines.
• However, I can't explain why serpent-xts-512 seems to be the way to go with cryptsetup while aes-xts the only cipher worth using.

4- Question

cryptsetup and TrueCrypt give completely different qualitative (relative cipher speed) and quantitative (actual speed of each cipher) results in in-RAM benchmarks.

• Is that something you have already noticed?
• Should I trust cryptsetup and use serpent-xts-512 cipher for speed?