MrBenchmark

Wednesday December 14, 2005

iGenCPU results on UltraSPARC T1 (T2000) and UltraSPARC IV+ (V490+)

Hi all;

This is an update on my previous entry, adding the UltraSPARC T1 CoolThread server T2000 and the V490+.The throughput increase between the UltraSPARC IV+ and the UltraSPARC IV is fairly proportional to the clock frequency.No surprise here. The simplicity of this microbenchmark does not allow taking benfits of many of the UltraSPARC IV+ innovations.

Regarding the T2000, please note that I am not afraid to publish the results. This is not a marketing blog...Indeed, this benchmark is not recommended for the UltraSPARC T1 due to the fact that 25% of the instructions are floating point operations (see two previous blog entries).

It does not prevent us to collect the data. Please remember that we want our customers to run the right platform for their workload. So, if your workload is generating more than 2% of floating point operations, the UltraSPARC T1 is probably not what you should choose....

Note : The column threads is the number of threads used to observe the highest throughput with a response time (RT) less than 100 ms.

Monday December 12, 2005

iGenCPU 2.1 results - V40z, V65x, V490 and V440

Hi all;

As promised here are our first iGenCPU v2.1 benchmark results. See previous blog entry for the benchmark description.
As reported by my pfp tool ,  this benchmark is producing about 25% of floating operations and 75% others...
Therefore, absolutely not recommended for a UltraSPARC T1-based T1000 and T2000...

This table will show us the performance obtained on this benchmark for four popular Sun Microsystems servers :
The V40z  single core , the V65x, the V440 and the V490 all using Solaris 10 .  Please note that this servers may be available
today at a higher frequency.

Note : The column threads is the number of threads used to observe the highest throughput with a response time (RT) less than 100 ms.

Friday December 09, 2005

MrBenchmark benchmarks : Opteron vs UltraSPARC IV vs UltraSPARC T1

Hi all;

Whiners came to me saying : "MrBenchmark : Enough theory, please give us some benchmark results.."
And I said, fine...so here we are ..I will publish some informal benchmark results in this forum. And Yes I will compare
UltraSPARC IV, IV+,  Opteron , UltraSPARC T1 and even Xeon !

Let me present the first microbenchmark of my serie . It is called iGenCPU. It is written in 100% pure Java. I am using Java 1.5

The iGenCPU benchmark is a JavaTM-based CPU micro-benchmark used to compare the CPU performance of different systems.
Based on a customized Java complex number library, the code is computing Benoit Mandelbrot's highly dense fractal structure using
integer  and floating-point calculations. The simplicity of the code as well as its non-recursivity allow a very scalable behavior using 
less than 64 Mb of memory per thread.

iGenCPU reports multiple statistics. We  are mostly interested in analyzing iGenCPU_Thp (how many fractals per second can we
 compute with this number of threads ?) and iGenCPU_RT (what is the average time needed to compute a complete fractal with this number of threads ?)

IgenCPU use the system this way as represented by my iTarget chart :




Next to come : our first iGenCPU benchmark result (table & diagram ): V40z (4xAMD Opteron @2.4Ghz  with 8GB RAM ) vs V490 (4xUltraSPARC IV 1.2Ghz 8GB RAM)



Dec 09 2005, 04:25:28 PM PST Permalink

Thursday December 08, 2005

How to demonstrate the value of the CoolThread UltraSPARC T1 servers (T1000 - T2000) to your boss ?


Well, after a very long entry presenting my pfp tool , here is a very short one...

To demonstrate the value of the CoolThread UltraSPARC T1 servers (T1000 - T2000) to your boss
there is only one thing to do : make her/him benchmark it using Sun Sim Datacenter
(yes ! your boss is gonna run a benchmark and she/he will like it ! )

How to do it and simulate all your Datacenter with UltraSPARC T1000 or T2000 ?
Very simple, download Sim Datacenter here , and run it on Solaris 9 or 10 !

What, you don't have Solaris 10 on your laptop ?
Get it right now on this Solaris page ...
Easy,no ? Dec 08 2005, 05:04:37 PM PST Permalink

Wednesday December 07, 2005

Is my workload recommended for a CoolThread UltraSPARC T1 server ( T1000 - T2000 ) ?



Since the pre-release and announcement of UltraSPARC T1 systems (T1000 - T2000),
our customers coming in the Sun Solution Benchmark Center have been very interested to know if their
application will work well on UltraSPARC T1. While assessing the multi-threaded nature of a
workload is easy using standard system tools, it is less straightforward to obtain at will
the amount and proportion of floating points instructions executed by a system. Some complex
tools exist but we would like to have a simple go/no-go binary that would answer
only this question. (If you are interested in a more detailed analysis of a cpu behavior, please
ask me about a great tool called ripc )

The key information coming from our UltraSPARC T1 engineers is the choice they had to make (because
of space limitations) to have a single floating point unit shared by the 8 cores (and 32 strands).
Please note that this challenge has been solved on the next release of this processor.

They tell us that in there best estimation any workload doing more than 2% of the total amount of instructions
using floating-points  will not be recommended for UltraSPARC T1. Between 1% and 2% is the gray area where
they recommend us to try because a number of the simpler FPU commands were moved to the
core and dont incur a 40 cycles penalty.


The idea of this article is to explain how to get this information and provide a simple tool
(for all UltraSPARC based systems).

The UltraSPARC III (or UltraSPARC IV core) has a maximum of four instructions that can
be fetched from cache in a clock cycle and a total of sixteen fetched instructions that
can wait for an execution unit to become available. Six parallel execution units exist on
the chip : one load/store unit, one branch unit, two identical integer Arithmetic Logical
Units, one add (and therefore substract) floating point unit named FA_PIPE (see FP 1
on the schema below and one multiply(and therefore divide) floating point unit named FM_PIPE.
(see FP 2 below).



For the UltraSparc III (and IV or IV+), multiple performance instrumentation counters are provided to analyze the CPU performance
behavior under load but for our purpose we need to consider only three of them :

1-The total number of instructions completed  not counting annulled, mispredicted or
trapped instructions. This is the Instr_cnt counter

2-The total number of instructions completed on the FA_PIPE. This is the FA_pipe_completion
counter.

3-The total number of instructions completed on the FM_PIPE. This is the FM_pipe_completion
counter.

Note that the counters 2 and 3 are also incremented for some type of VIS instructions. Therefore,
they have to be considered only as estimations.

For the UltraSPARC T1 based systems, it is simpler as the single counter FP_instr_cnt is directly provided.


As you already deducted, we will be able to determine the percentage of floationg point
operations with the formula :

%FP_ops = 100 * (FA_pipe_completion + FM_pipe_completion) / Instr_cnt

We are also able to provide this simple heuristic :

if ( %FP_ops < 1%) -> Recommended for UltraSPARC T1
else if (%FP_ops  between 1% to 2%) -> Possible fit for UltraSPARC T1
else -> Not recommended for UltraSPARC T1

To do this, here is a program named pfp that you can use as pfp <duration in seconds>
If you are on a T1000 or T2000 system, please use the flag -n as this program does not detect the cpu
type in its first release.Please remember to run your workload first and while it is running,
use this program as shown below.

paris # ./pfp 30
We observed 22756679 instructions separated in 0.20% floating point and 99.80% others
This workload is recommended for UltraSPARC T1 systems.

ontario # ./pfp -n 30
We observed 342593950 instructions separated in 0.77% floating point and 99.33% others
This workload is recommended for UltraSPARC T1 systems.

If you just want the percentage of floating point instructions, you can also do
paris # ./pfp -s 30
0.20

Finally, you can also use the tool on Solaris 8 or Solaris 9 with :
Dtrace # ./pfp -ps 30
1.97

The binary of this tool can be found here.


Dec 07 2005, 05:02:21 PM PST Permalink