Hex-Core Processors

[G Gabriel]

Anyone using hex core based machine?
Any comments regarding performance, shortcomings, alpha compatibility..etc ?
Thanks

[jdrake]

Re: Hex-Core Processors

I don't have a hexa core but I do have a machine with dual quad cores w/ Alpha. I wouldn't expect it to be much different though.

Performance is good, but Alpha doesn't run many threads unless you create your own, so your basically stuck in one or two cores. But other processes running on the computer are less likely to get in the way.

[G Gabriel]

Re: Hex-Core Processors

Thanks. I suppose what you have is a server.

[David Martin]

Re: Hex-Core Processors

Thanks. I suppose what you have is a server.

Not necessarily, my Dell Precision 490 has Dual Quad core Xeons

[G Gabriel]

Re: Hex-Core Processors

Thanks. Seems like a lot of horsepower.
The dilemma I have, and I suspect many others do, is that I don't want to buy a Lamborghini or a Formula one car clocked to run at a speed of 250 MPH and drive it through the back alleys of New Orleans or on I-10 on rush hours.

If you have hex-core or dual quad and the software is not designed with an algorithm to parallelize to take advantage of the multi-core and/or if the parallelization is not optimal, then you wasted a lot of money on your Lamborghini.

Does anyone know or read anything about alpha being parallelized for multi-core? Most software are trying to play catch up with the new technology and my guess the answer is no. For now, my main purpose of building a new powerhouse of a computer is the fact that I run multiple applications simultaneously all of which are memory and processors hogs and secondly it won't be long before the software catches up ... and then some new technology will come up. Nano? Not to mention, you might not need any of this power if those guys succeed in selling you on the idea of cloud computing.

[martinwcole]

Re: Hex-Core Processors

Hey Gabe,

I think certain factors play a role in actual performance - like how many files do you have on your development computer, HD speed, bus and memory.

For example, I have a Zeon box I paid 4,000 for about 18 months ago, with 32 bit xppro, 4 gig ram, 10,000 rpm drives, 1333 bus, etc. On my system I have approxamately 1.7 million files, as reported by my virus program. A script I often use as a benchmark, that rebuilds from scratch the indexes for 364 tables with one or more indexes each takes about 58 seconds.

On a client zeon box, for about 1,600.00, xppro 32 bit, with maybe 200,000 files, it runs in about 57 seconds. I attribute the difference to the number of files, and how much extra work windows has to keep track of the FAT.

At a different client, on a new 2008R2 Standard Zeon box, 64 bit, 8 GIG ram, 7200 RPM drives, there is no discernable difference in performance of the same app on my machine and theirs.

At another client, who bought a new W7 Home 64 bit, (probably at Kmart,) for around 500.00 running Version 5 of Alpha, it performs slower than mine.

At your level of expertise, I'm sure you are aware of many other factors affecting actual performance.

I think most any decent system for around 2,000 will run darn near as well as any other. Some of my clients have me buy their systems for them - I got a zeon quad 2.3 GIG, 3 gigs ram, xppro 32 bit, 10,000 RPM drive ata2, 3 years gold support 24/7 4 hour response, for 1,600.

The 2008R2 server, with 1 terabyte 7200 rpm drives, raid, 10 seats and 10 T/S seats and 2 years 24/7 4 hour gold support I got delivered for 3,700.00.

[G Gabriel]

Re: Hex-Core Processors

The idea of multi-core came out of necessity not out of progression and that's why it's a bit fascinating but tricky. It's more like team work. Sometimes team work is good, sometimes is counter-productive. Sometimes it's better to delegate sometimes it's better to just do it yourself and get it over with.

As the chip engineers ran into limitations on the chips (for now) what can they do? After all, there is so much you could thread that silicon before your run into overheating problem and interference. So what do you do? Answer: Add more chips and divide the work amongst them. That's the tricky part. How do you divide the work so that in the end it's more not less productive?

The chip manufacturers devised ways to do so but in the end it's up to the software. So let's say if you are printing a large file from alpha that requires lots of calculations. Alpha might run the whole thing on one thread, or it might break it down to 2 or 3 or 4 threads. Alpha runs multiple threads, my understanding is, for multiple tasks. For instance, if you are running a script that does one thing and another that does another they run concurrently not in sequence. But do they run on 2 different cores? Or on the same core? And what if the task is small? Would it be better to run on one instead of 2 cores?

There are way too much debate out there on how and when to break down the threads and so many rules, jargon and laws from Amdahl's law, Gustafson's Law, instruction level parallelism, instruction pipeline, thread level parallelism, Block multi-threading, Interleaved multi-threading, Simultaneous multi-threading and one of my favorites: fine-grained decomposition of a problem.

Martin, the example you used is excellent since virus scanning is one of those that is processor-intensive. If the scanning program is designed to run on 4 core, you could expect the time to diminish significantly limited only by: 1-The part that cannot be parallelized (Amdahal's law) and 2-transfer rates and perhaps to a less extent cache. Assuming the scanning program can be parallelized in the most part, you should be able to run it in 15 seconds or so instead of 59.

But back to alpha. In alpha and similar softwares which most likely fall under "hard to predict code", or those in which there is too much dependencies, parallelization and multi-threading among multi-core is probably of little utility if not down right impossible.

Hence, my premature conclusion that if you are using your machine primarily for such applications, the K-Mart machine takes the cake.

[DaveM]

Re: Hex-Core Processors

It all goes back to how much you want to pay for performance.

At least it was a new Kamart 500.00 machine.

A few years ago, I installed F&I software and woulkd go a site to find a 5-6 year old computer that was worn out, behind the times, and full of garbage. When asked, the buyer would tell me they bought a new computer for the house so the kids could play on it and brought the old one in to run their 200,000 to 2,000,000+ business. This happened many many times.

The printers required to run the forms was at least an okidata 320. They would come up with all kinds of other printers from an old inkjet to a cheap dot matrix that could not print the multicopy forms needed. (Some forms are 7-8 copys thick). All to save 1-200 dollars.



.

[jdrake]

Re: Hex-Core Processors

If you have a hexa-core processor running Alpha, processing power is not going to be your bottleneck. My experience has always showed me that a faster bus and hard drive is worth more per dollar than a few more processor mhz or cores for an standard everyday use computer.

Even though Alpha may not use many threads, your windows box is still running at least a few dozen other programs and services in the background that could be using the other cores.

[G Gabriel]

Re: Hex-Core Processors

Agreed. Thanks.
Hope Windows does not need a core just for itself.

[martinwcole]

Re: Hex-Core Processors

I totally agree on the bus and HD being major factors. When the pocket book will bear it, I get 15,000 RPM SCSSI drives - they last forever - still have a system, maybe 9 years old, SCSSI's still running.

[RRTRACKS]

Re: Hex-Core Processors

Being in the process (a very long one) of learning Alpha 5, up to this point in time there is not much in the way of questions or contributions I have had for this board. Even though I do not understand much, I do look at it frequently as both the people along with the problems brought up and solved are interesting. A few questions related to this topic provided below.

Does anyone have any performance tests on a caching program with an Alpha 5 application? You can also mirror data in RAM but I know little about that. Maybe someone could comment on the topic.

If anyone has a spare computer to tinker with, Romex Software is currently beta testing a caching program that can utilize RAM. It also can use what they call Invisible Memory (IM), being the portion of memory above the 4GB limitation most 32 bit Windows OS have.

Thanks,
Rich

[G Gabriel]

Re: Hex-Core Processors

Invisible memory refers to that part of the memory that is not seen nor recognized by your OS but that applies to OS using 32bit & RAM of 4GIG. I don't suppose you want to use 32bit anymore.

[RRTRACKS]

Re: Hex-Core Processors

G,
I do not understand Windows very well and may be mistaken, but I believe a 32bit Windows OS only sees about 3 of the first 4GBs. It can access up to 4GB but I do not know how you get the last GB using Windows. When I upgraded from Windows XP to Windows 7 my operating system would only see 2 of the 4 GB installed. GREAT! This was before anything was installed beyond the Windows OS.

What I did to resolve this was create a 2 GB RAM drive and assign virtual memory to it. The virtual memory is not quite as fast OS RAM but five to ten times faster than the hard drive it replaced. Romex Software�s Ramdrive Suite costing about 20 dollars is what I used to accomplish this. There might be freeware or a better software package out there, but I am happy with what I got. For my usage at this time 32 bit Windows is fine.

My question though was whether or not anyone here has had any experience with Alpha5 and disk caching software or knew anything about using RAM to mirror data on the hard drive.

Thanks,
Rich

[G Gabriel]

Re: Hex-Core Processors

I don't know how much RAM Windows7 sees or utilizes. I have to research that a little further. I don't have Windows7 yet. I will when I build a new machine but I appreciate any information you have in that regard. I have not done any testing on alpha & RAM mirroring but that would be something worthwhile. Perhaps someone from alpha could fill in these gaps.
You bring up very good points which serve to emphasize my notion that more does not always mean more. One thing for sure, more means more money.