High-end systems

I have several high-end PC's. Is there a way to run multiple Seti@home clients
simultaneously on a single computer?

If you have a system with a P4 that supports Hyperthreading then you can run
two instances of the SETI Client. I use SETI Stash and run one instance with
CPU set to CPU 0 and the other set for CPU 1. Works great. My OS is WINXP
home.

If you have a system with a P4 that supports Hyperthreading then you can run
two instances of the SETI Client. I use SETI Stash and run one instance with
CPU set to CPU 0 and the other set for CPU 1. Works great. My OS is WINXP
home.

I have several high-end PC's. Is there a way to run multiple Seti@home
clients
simultaneously on a single computer?

I have several high-end PC's. Is there a way to run multiple Seti@home
clients
simultaneously on a single computer?

Gary Heston wrote:

In article ,
chrBobsci wrote:
I have several high-end PC's. Is there a way to run multiple Seti@home
clients simultaneously on a single computer?

You can, but the only situation where that's beneficial is on
multiprocessor systems with Intel Xeon CPUs which support hyperthreading.

On a single CPU non-hyperthreading system, once instance of the client
will use all the available CPU cycles; running two just splits the cycles
between them.


Gary

nonsense, Any multi-cpu system (for which archetecture the seti@home cli has
been written for) can run more than once instance of seti. You dont need
Xeons, you dont need Hyperthreading. ie: if there is a CLI version for a
single cpu version of your system and you happen to have that type of cpu
in a multi-cpu system then you can beneficialy run an instance per cpu. HT
is just a tecnology that lets you share part of the cpu core so in effect
one cpu becomes "almost" as capable as having 2 cpu cores on board. Its
less than 2 complete cpu's but its more than 1 cpu - in effect the 2
logical cpu's perform somewhat better overall than 1 cpu but not as good as
2 cpu's. HT is dual cpu on the cheap.
Eric

Gary Heston wrote:

In article ,
chrBobsci wrote:
I have several high-end PC's. Is there a way to run multiple Seti@home
clients simultaneously on a single computer?

You can, but the only situation where that's beneficial is on
multiprocessor systems with Intel Xeon CPUs which support hyperthreading.

On a single CPU non-hyperthreading system, once instance of the client
will use all the available CPU cycles; running two just splits the cycles
between them.


Gary

nonsense, Any multi-cpu system (for which archetecture the seti@home cli has
been written for) can run more than once instance of seti. You dont need
Xeons, you dont need Hyperthreading. ie: if there is a CLI version for a
single cpu version of your system and you happen to have that type of cpu
in a multi-cpu system then you can beneficialy run an instance per cpu. HT
is just a tecnology that lets you share part of the cpu core so in effect
one cpu becomes "almost" as capable as having 2 cpu cores on board. Its
less than 2 complete cpu's but its more than 1 cpu - in effect the 2
logical cpu's perform somewhat better overall than 1 cpu but not as good as
2 cpu's. HT is dual cpu on the cheap.
Eric

"Eric" wrote in message
news:JofOb.76524$nt4.107044@attbi_s51...
Gary Heston wrote:

In article ,
chrBobsci wrote:
I have several high-end PC's. Is there a way to run multiple Seti@home
clients simultaneously on a single computer?

You can, but the only situation where that's beneficial is on
multiprocessor systems with Intel Xeon CPUs which support
hyperthreading.

On a single CPU non-hyperthreading system, once instance of the client
will use all the available CPU cycles; running two just splits the
cycles
between them.


Gary

nonsense, Any multi-cpu system (for which archetecture the seti@home cli
has
been written for) can run more than once instance of seti. You dont need
Xeons, you dont need Hyperthreading. ie: if there is a CLI version for a
single cpu version of your system and you happen to have that type of cpu
in a multi-cpu system then you can beneficialy run an instance per cpu. HT
is just a tecnology that lets you share part of the cpu core so in effect
one cpu becomes "almost" as capable as having 2 cpu cores on board. Its
less than 2 complete cpu's but its more than 1 cpu - in effect the 2
logical cpu's perform somewhat better overall than 1 cpu but not as good
as
2 cpu's. HT is dual cpu on the cheap.
Eric

Gary is absolutely correct in stating that you should only run one instance
of the SETI Client per CPU. The only exception is if you have at least 1Mb
of L2 cache. In this case you can run two instances because there are no
cache misses to interfere with performance. SETI is memory intensive and
running two instances will cause a lot of CPU stalls due to cache misses.
The HT CPUs don't seem to be impacted by this problem because each HT
virtual CPU has it's own L2 cache. For best throughput with SETI, run the
CLI version and a local caching program to keep the client supplied with
WUs.

Mike Ober.

"Eric" wrote in message
news:JofOb.76524$nt4.107044@attbi_s51...
Gary Heston wrote:

In article ,
chrBobsci wrote:
I have several high-end PC's. Is there a way to run multiple Seti@home
clients simultaneously on a single computer?

You can, but the only situation where that's beneficial is on
multiprocessor systems with Intel Xeon CPUs which support
hyperthreading.

On a single CPU non-hyperthreading system, once instance of the client
will use all the available CPU cycles; running two just splits the
cycles
between them.


Gary

nonsense, Any multi-cpu system (for which archetecture the seti@home cli
has
been written for) can run more than once instance of seti. You dont need
Xeons, you dont need Hyperthreading. ie: if there is a CLI version for a
single cpu version of your system and you happen to have that type of cpu
in a multi-cpu system then you can beneficialy run an instance per cpu. HT
is just a tecnology that lets you share part of the cpu core so in effect
one cpu becomes "almost" as capable as having 2 cpu cores on board. Its
less than 2 complete cpu's but its more than 1 cpu - in effect the 2
logical cpu's perform somewhat better overall than 1 cpu but not as good
as
2 cpu's. HT is dual cpu on the cheap.
Eric

Gary is absolutely correct in stating that you should only run one instance
of the SETI Client per CPU. The only exception is if you have at least 1Mb
of L2 cache. In this case you can run two instances because there are no
cache misses to interfere with performance. SETI is memory intensive and
running two instances will cause a lot of CPU stalls due to cache misses.
The HT CPUs don't seem to be impacted by this problem because each HT
virtual CPU has it's own L2 cache. For best throughput with SETI, run the
CLI version and a local caching program to keep the client supplied with
WUs.

Mike Ober.

In article JofOb.76524$nt4.107044@attbi_s51, Eric
writes
Gary Heston wrote:

In article ,
chrBobsci wrote:
I have several high-end PC's. Is there a way to run multiple Seti@home
clients simultaneously on a single computer?

You can, but the only situation where that's beneficial is on
multiprocessor systems with Intel Xeon CPUs which support hyperthreading.

On a single CPU non-hyperthreading system, once instance of the client
will use all the available CPU cycles; running two just splits the cycles
between them.


Gary

nonsense, Any multi-cpu system (for which archetecture the seti@home cli has
been written for) can run more than once instance of seti. You dont need
Xeons, you dont need Hyperthreading. ie: if there is a CLI version for a
single cpu version of your system and you happen to have that type of cpu
in a multi-cpu system then you can beneficialy run an instance per cpu. HT
is just a tecnology that lets you share part of the cpu core so in effect
one cpu becomes "almost" as capable as having 2 cpu cores on board. Its
less than 2 complete cpu's but its more than 1 cpu - in effect the 2
logical cpu's perform somewhat better overall than 1 cpu but not as good as
2 cpu's. HT is dual cpu on the cheap.
Eric

I think you have just repeated what Gary stated earlier :0 (

For SMP systems using Intel duals (P2s & P3s) or AMD Athalon MPs an
instance of the CLI can be run on each physical processor. At least that
is how I run my dual P3 system. The AMD is acknowledged to be superior,
having the better FPU.

For single proc systems then 1 instance of the CLI can be run, except
for HT ready P4s, where 2 instances can be run. At least that is how I
run my only single proc box.

For systems like dual Intel Xeons 4 instances of the CLI can be run. One
on each of the physical processors, one on each of the HT virtual
processors. At least that is the way I run my server box.

The downer on Intel dual proc systems is the increased CLI times due to
shared resources (bus, RAM, etc) between each processor. I understand
the AMD dual proc systems since the Athalon 64 have sorted this with a
pipeline to each processor. Only memory shared?

--
John Clark

In the "reply to", replace either "fredclark" or "Workgroup" with "jonclark" for
direct e-mail.