Comparing Quality of Results of FPGA CAD Tools

I'm not sure what this is telling us. It looks like you compared the fmax of some designs in VirtexII (quite old technology) and StratixII (quite new/future technology), and observed that the StratixII implementation was faster.

From this you deduced that the Altera synthesis was better.

What am I missing here?

Let's see: - name is John Smith - full professor at US school, but no mention of school name - yahoo e-mail address - Having attended engineering school, I realize that English is not a top priority for students or faculty. Even so, the phrase "I would like to shed my experiences" is not exactly confidence-inspiring.

I suppose this could be legit, but the ol' bogosity meter is sitting near full scale. For starters, could you give us the university and department names?

Thanks, Bob Perlman Cambrian Design Works

My B.S. detectors are hitting full scale deflection on this one!

"John Smith"? Pseudo-anonymous name, anonymous email, simple grammatical errors, explicitly saying "full professor", not identifying which school... nah....

But why?

Perhaps the author is the Prof. John Smith that google turns up here :)

-jg

From his IP address he's one CustName: J VASUDEVAMURTHY

I found an email address on Google

snipped-for-privacy@Xilinx.COM

How very strange!

How exactly is Virtex II considered "old" technology. Virtex 2 is the newest, fastest parts that Xilinx has. Virtex2pro may be a bit newer/faster, but they are not the same generic parts, they all include Power PC CPUs internally driving up the cost considerably.

How'd you figure that then?

I guess "old" was the wrong term. I was just pointing out that it might be more appropriate to compare StratixII with Virtex4.

Pete,

You are correct. 4VLX25 ES samples are available, too.

Aust>

RP:

There is no employee at Xilinx by that name.

I think the BS meter just pegged and broke!

Aust> From his IP address he's one

Is that possible? Is Virtex4 supported by the current tools?

Rick,

If you subscribed to the early access program, you would be using tools to develop your Virtex 4 design.

Since that is a select few (one might even say insignificant number compared to the total number of users), I would not expect anyone out there to know about it, unless they were a customer who had expressed an interest in being an early adopter of the latest technology (also because if someone was part of the program, they sign the agreement not to divulge).

Once the product is announced, and all software enabled, the good news is that there were many who had gone through it before you did, and helped hammer out all of the bugs.

We greatly appreciate those who volunteer to be early access customers, and we hope that they feel that we have done everything we can to have supported them, as this is definitely something that benefits everyone.

Aust> Pete Fraser wrote:

Not true. The Virtex-IIPro fabric is almost identical with Virtex-II, with PowerPC and Multi-gigabit transceivers added to it. But the more advanced processing makes V-IIPro both faster and -lo and behold- even cheaper than the same logic in Virtex-II. So you can ignore ("throw away") the PPC and the MGTs, and V-IIPro is still less expensive than Virtex-II. If you use the PPC and/or the MGT, it is just that much more of a bargain. Just one of the benefits of Moore's Law and aggressive process innovation...

Peter Alfke

Try 1995, perhaps - it could have been faked but it's on the net.

Ok, so I think the answer is "in general, the tools do not yet support the Virtex 4 parts". I understand that you have a special program for "early access". But the question was in the context of doing a comparison. Unless the OP was one of the "early adopters" he would not be able to do the comparison.

Aust>

Yes, you can ignore and throw away the PPC. But you can't get the part for the same price as not having the PPC. So comparing the V2P would not be very apples and oranges. Of course there are lots of ways a V2 to StradixII is not apples to oranges, but in terms of the current parts designed for speed and in the same price range, I think this is the best comparison until V4 is actually out (or at least in the current release of the software).

It would have been nice to detail precisely all versions of the development tools and all device characteristics that you used to be sure that you don't compare an old XST w/ an old technology w/ a small FPGA to a new QNS w/ a new technology w/ a big FPGA ;-) For a professor, you're quite vague on the conditions of your experiments.

Eric

This argumentation is getting a bit weird. So we offer higher performance at a lower price ( in Virtex-IIPro), but rickman does not want to use them as a benchmark, because they wouldhave been even cheaper without the PPC and MGT.

Yes, and even cheaper without all the multipliers, and without the BlockRAM and the DCM, not to mention all the 50 different I/O options. And half the routing is never used, and who needs LUT-RAM and SRL16s ? Where should we stop in stripping things out to make you happy ?

Peter Alfke

Scarcasm is always a nice way to discuss a topic.

I checked web pricing and the V2Pro is a bit cheaper than the V2. The last time I had checked it was not. Regardless, V2 is not "quite old technology" and it is also not the V4 which is what Pete Fraser was proposing and I was disputing the availability for comparison. Austin said that "special" customers have been given the software to evaluate. So unless we get some of the "special" customers in this discussion, we will have to use the old Xilinx technology for our comparisons.