( ESNUG 305 Item 11 ) -------------------------------------------- [11/18/98]
Subject: ( ESNUG 304 #6 ) Pros & Cons To Running EDA On SUN Compute Farms ?
> We are investigating converting our individual high performance desktop
> Sun workstation computing model to a compute server, specifically Sun's
> E10000 server with multiple processors and up to 1 Gig of RAM on each
> processor. Does anyone have any experience with this type of compute
> server for EDA applications? What are the pros and cons of a single
> compute server model versus a "compute farm" network of high performance
> workstations?
>
> - Shuhui Lin
> Alcatel Telecom Raleigh, NC
From: Mike Coffin <mhc@Eng.Sun.COM>
John,
I'm the project lead for Dream, which is the load-balancing system for
the Sun Microelectronics ranch.
Here are some advanatages to a compute farm of high performance
workstations:
- After the workstations are a couple years old and no longer
considered fast, you can pull them out of the ranch and give them
to users. Hard to do with a E10000.
- An E10000 is a single point of failure. They are pretty reliable,
but if one goes down, or has to be off line for some reason, your
entire engineering staff may be idled.
- The workstations can be replaced incrementally with faster
machines---you don't have to upgrade everything at once.
- If you do not need the parallel processing capability of the
E10000, you are paying somewhat more for the same amount of CPU
horsepower than equivalent workstations. On the other hand, see
below.
Advantages of big servers like the E10000:
- Less system administation because fewer machines.
- Less space required.
- Less networking required.
Personally, I like Sun Microelectronics' model: a compute ranch of high
performance workstations that also contains some big servers, including an
E10000. :-)
- Mike Coffin
Sun Microsystems
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From: Peter.Denyer@Eng.Sun.COM ( Peter Denyer )
John,
Take a look at my whitepaper at
http://www.sun.com/technical-computing/Publications/cfarm.html
It expands a bit on what Mike put forth. We have a couple of big compute
farms here at sun. The productivity increase in this style of EDA computing
over a desktop-centric compute model is quite amazing. Let me know if you
have additional questions on this.
- Peter Denyer
Sun Microsystems
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From: alain_raynaud@mentorg.com (Alain RAYNAUD)
John,
We made the same change, and I like it a lot. Before, when we needed to run
a big job, it was a mess, both network and CPU-wise. Now we have one big
iron: it's as if you had the whole system for yourself. Of course it has
to be dimensioned very carefully otherwise everybody will be slowed down.
But you save a lot on network bandwidth (CAD jobs tend to rely heavily on
I/O). You also never swap (with several GB of main memory), so your tasks
finish earlier. Basically, you have in one place very fast disks (RAID),
the I/O that goes with it, and a powerful CPU (think L2 cache). I would
recommend no more than 30 engineers working on one such machine. But you
don't need one CPU per user, that's where you save a bit.
The problem: any downtime and your whole department is on holidays. But
it's so much easier to administer too. But I'm not saying it's cheaper
(it probably isn't). One of the drawbacks is upgrade: a powerful
configuration today will seem low-end in one year. It's easier to replace
workstation after workstation, but changing the big iron is not always so
cost-effective. Try to negociate a good upgrade deal.
- Alain Raynaud
Mentor Graphics Meta Systems Division
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From: "Jim Avant" <javant@homewireless.com>
Hi John,
This is in response to Shuhui Lin's question about a Sun server vs.
individual workstations. I've been meaning to write this for awhile and
I finally got a little break in the action so here goes:
At my last company, I put together a hybrid system with a big server and
some Sparc 20s. This was supplemented with fairly high-end PCs which
everyone had. At the peak of the design effort, we had 3 ASIC designs
and about 8 large FPGA designs going on. At the time we used FPGA
Compiler on the Sparcs. Today I would do all FPGA designs totally on
the PCs (with Synplify).
I've found that wherever you go you have UNIX bigots (& Linux) & PC
bigots and you're just fooling yourself if you try to convert them. The
best you can do is have the UNIX people typing on a workstation keyboard
and the PC guys on PCs. If you set up your networking right and use NFS
& X server S/W you can create an environment where everyone is fully
productive (which is much more important than saving a few bucks). The
PC folks did all the front-end development on the PC and then logged
into the server for the rest. The workstation guys did all their
development work on the workstation and used PCs for documentation, etc.
We didn't use WABI or anything like that but you could possibly use this
to eliminate some PCs (but why bother? give the UNIX guys the
hand-me-down PCs).
We were just starting to worry about version control and were looking at
using ClearCase with the database being on the UNIX server. In general,
I've found implementing revision control in an ASIC design environment
about as easy as herding cats.
Another goal was to have an environment conducive to telecommuting (we
had to call it tele-overtime because telecommuting was against company
policy). One point that I'd like to make that has been a particular
boon of having PCs in the loop is this: The traditional way of kicking
off sim's & synthesis runs is to use telnet & X-windows server software
from home to get into your server or workstation but the problem is that
when you disconnect, you lose the connection to your windows. You
examine log files to determine progress. Now I dial into our RAS server
and connect to my PC with pcANYWHERE (over TCP/IP with full security)
and work there. I can disconnect and reconnect at will and everything's
still there! And it's still there when I come in in the morning. This
is very handy, especially with ISDN or better connection rates.
One thing we stumbled on early on was the UNIX/DOS text file
differences. We worked with several vendors to make sure their software
didn't care how the lines were terminated. Today only Synopsys has
totally ignored this request (there may be others that I don't know of).
The key to working in a mixed environment is that you DON'T CARE whether
the file is stored on a hard disk on a UNIX workstation or a PC. Keep
the file in the format that IT'S most comfortable in without regard to
where it's stored. We store MSWord files on workstations and edit UNIX
text files on PCs all the time. Text editors like pfe understand this.
Crisp is a great text editor that's available on both UNIX & NT
platforms but they just don't understand this point (believe me I've
tried).
One last point. If anyone tells you that modern PCs running NT 4.0 are
inherently unreliable please disregard this bigotry. We have PCs that
run for months without being restarted. A good network systems
administrator is worth his/her weight in gold and can make any
reasonable system run smoothly.
These opinions are my own and have changed somewhat over the years. I
hope this helps someone.
- Jim Avant
Homewireless Norcross, GA
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From: Jean-Marc Calvez <jean-marc.calvez@st.com>
John,
I have seen both models... Right now, I know that for the money needed to
ensure decent working conditions for 4 persons in a centralized environment
(two Sun UltraII 336MHz processors, 2 GB RAM, one motherboard, 2*18G disks)
I could get 4 ultra60/300 workstations with 512 MB RAM (and those are OK for
simulation/synthesis, but probably weak on memory and disk for P&R). In
other words, more computing power (in the form of more processors), with
screens, keyboards and mouses thrown in as bonuses.
Still, I have no answer on which one is "better overall".
- Jean-Marc Calvez,
STMicroelectronics Grenoble, France
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