In article <1radnX8dq9ywT8bVnZ2dnUVZ_sDinZ2d@comcast.com>, General Schvantzkopf <schvantzkopf@yahoo.com> wrote:>On Fri, 20 Jun 2008 07:51:58 -0700, Mike Treseler wrote: > >> General Schvantzkopf wrote: >> >>> The Altera ModelSim is dog slow which is to be expected, I'm sure that >>> Mentor has deliberately crippled it. >>> >>> NC, Linux 0:06:34 >>> Questa, Linux 0:07:15 >>> Questa, XP 0:18:14 >>> Altera ModelSim, Linux 1:00:13 >> >> >> Thanks for taking the time to run the test and for sharing the results. >> Interesting that speed is roughly proportional to the cost of the >> license. >> >> While the oem version is "dog slow" in this lineup, it is still quite >> useful for debugging rtl when all the licenses are checked out. >> >> -- Mike Treseler > >What should be of most interest to anyone who is looking to buy a serious >simulator is the difference between Linux and XP. I ran the same version >of Questa on both Linux and XP with the same license. Questa runs three >times as fast on Linux as it does on XP. I'm pretty sure that the time >difference can be attributed to the performance of the Linux file system >(EXT3) vs the XP file system (NTFS). The real purpose of my investigation >was to compare various Virtualization tools. I gathered the numbers that >I posted before on the native OSes to give me a baseline. I then ran the >NC and Questa tests on VMware Server, VMware Workstation and KVM. When >using a virtual disk all of the VMs were only 5-10% slower then native, >KVM being the fastest. However if I used a host machine directory that >was accessed via NFS the performance dropped dramatically, about 2.5X for >VMware and 5X for KVM. VMware's shared folders were just as fast as >VMware's virtual disk performance i.e. about 10% slower then the native >performance. The NFS mounted host directory performance on VMware was >about the same as native XP performance which leads me to believe that >XP's problem is it's file system.I wonder if it's core XP or if it's the filesystem itself. There's a Windows-XP port of EXT2 available. It would be amusing if it was faster than NTFS. So was your virus scanner on during the simulation :-) The answer is to just use Linux. -- /* jhallen@world.std.com AB1GO */ /* Joseph H. Allen */ int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0) +r*57)/7,q=q?q-1?q-2?1-p%79?-1:0:p%79-77?1:0:p<1659?79:0:p>158?-79:0,q?!a[p+q*2 ]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817;)printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}
which commercial HDL-Simulator for FPGA?
Started by ●June 18, 2008
Reply by ●June 20, 20082008-06-20
Reply by ●June 20, 20082008-06-20
On Fri, 20 Jun 2008 15:53:44 +0000, Joseph H Allen wrote:> In article <485BC40E.3020008@gmail.com>, Mike Treseler > <mtreseler@gmail.com> wrote: >>General Schvantzkopf wrote: >> >>> The Altera ModelSim is dog slow which is to be expected, I'm sure that >>> Mentor has deliberately crippled it. >>> >>> NC, Linux 0:06:34 >>> Questa, Linux 0:07:15 >>> Questa, XP 0:18:14 >>> Altera ModelSim, Linux 1:00:13 >> >> >>Thanks for taking the time to run the test and for sharing the results. >>Interesting that speed is roughly proportional to the cost of the >>license. >> >>While the oem version is "dog slow" in this lineup, it is still quite >>useful for debugging rtl when all the licenses are checked out. >> >> -- Mike Treseler > > It would be interesting to see Icarus in this list. Also Verilator...I haven't been able to get Icarus to work, it's not complete enough to run any of our testbenches. We aren't doing anything fancy, in fact all of our code is strict Verilog 95 it's not even 2001.
Reply by ●June 20, 20082008-06-20
On Fri, 20 Jun 2008 10:52:13 -0500 General Schvantzkopf <schvantzkopf@yahoo.com> wrote:> The NFS mounted host directory performance on VMware was > about the same as native XP performance which leads me to believe > that XP's problem is it's file system.That's hardly a convincing proof that all the performance increase is due to file system. In my experience, NFS does slow down ncsim a lot when I turn on the waveform dumping, but without waveform dumping, there is no noticeable performance difference after the design elaboration. I'm not saying filesystem isn't part of it, but for a long simulation with no data logging, 99% of the time the simulator is not doing file I/O. Rather, I believe the following two play a more major role in the speed difference: 1. Context switching. Linux is very very good at this. In a workstation environment where I/O interrupts happen hundreds of times a second, context switching happens everytime the CPU switch to run from one process to the next one. What's good about the Linux kernel is that you can tune a lot of things: the amount of interrupts, how frequently the kernel service them, and how pre-emptible the kernel is. A fine-tuned batch server can very fast. Not so much help from XP. I believe Windows 2000 does have an option to choose between server and desktop mode, but not sure what difference it makes. 2. Memory management. Linux is again very very good at this. Filesystem caching and virtual memory management works hand-in-hand. My 1GB RAM workstation ran 99.9% of time without going to swap partition, whereas in Windows XP, the same workstation constantly sees harddrive thrashing, especially after running a very memory intensive job. -- Faster, faster, you fool, you fool! -- Bill Cosby
Reply by ●June 20, 20082008-06-20
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 General Schvantzkopf wrote: | I haven't been able to get Icarus to work, it's not complete enough to | run any of our testbenches. We aren't doing anything fancy, in fact all | of our code is strict Verilog 95 it's not even 2001. Current snapshots are much improved, and bug reports are welcomed. - -- Steve Williams "The woods are lovely, dark and deep. steve at icarus.com But I have promises to keep, http://www.icarus.com and lines to code before I sleep, http://www.picturel.com And lines to code before I sleep." -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFIW+XmrPt1Sc2b3ikRAtL9AKCykWIDYFWQkNqwfjcAJUgXewEa0wCgxqwt 6U/NtBgPoBg4Y7aF5Ki6NsY= =YODt -----END PGP SIGNATURE-----
Reply by ●June 20, 20082008-06-20
Patrick Dubois wrote:> I really like to create a schematic top level with blocks that are > either more schematics themselves or directly vhdl blocks.I agree with rickman on the notion of a pure HDL hierarchy, but, like you, I also like to see structural views at all levels, including the top. However, I don't like to edit or to maintain graphical sources. I let the quartus rtl viewer draw my schematics based on my synthesis code alone. I can bring it up live to drill down module by module or print out pdfs at any level like this: http://mysite.verizon.net/miketreseler/uart.pdf http://mysite.verizon.net/miketreseler/stack.pdf> The state-machine editor in Active-HDL is another story. To me simple > state machines don't need to be represented by a diagram to be > understood. On the other hand, large ones are hard to represent in a > diagram. So in the end I only write vhdl state machines.Yes, a case statement is easy to write, read, and sim. Drawing curvy arrows and attaching equations is fun once. -- Mike Treseler
Reply by ●June 20, 20082008-06-20
> On Fri, 20 Jun 2008 07:51:58 -0700, Mike Treseler wrote: >> While the oem version is "dog slow" in this lineup, it is still quite >> useful for debugging rtl when all the licenses are checked out.General Schvantzkopf wrote:> What should be of most interest to anyone who is looking to buy a serious > simulator is the difference between Linux and XP.I thought maybe that went without saying. It is the main reason I maintain an SE license. Not only is it faster in linux (your numbers look about right to me), but I can take advantage of the ease of scripting make and vsim commands to do things like daily builds and verification from an svn repository.> I ran the same version > VMware's shared folders were just as fast as > VMware's virtual disk performance i.e. about 10% slower then the native > performance.Thanks for the VMware info. I'm still old-school with two optiplex boxes and a kvm switch. -- Mike Treseler
Reply by ●June 20, 20082008-06-20
On Fri, 20 Jun 2008 10:07:19 -0700, Jason Zheng wrote:> On Fri, 20 Jun 2008 10:52:13 -0500 > General Schvantzkopf <schvantzkopf@yahoo.com> wrote: > >> The NFS mounted host directory performance on VMware was about the same >> as native XP performance which leads me to believe that XP's problem is >> it's file system. > > That's hardly a convincing proof that all the performance increase is > due to file system. In my experience, NFS does slow down ncsim a lot > when I turn on the waveform dumping, but without waveform dumping, there > is no noticeable performance difference after the design elaboration.It's not NFS that's the problem with the VMs it's the virtual IO performance. I looked at the effect of NFS alone by using a directory that was mounted on a second Linux machine that was connected to my test machine via gigabit Ethernet. The degradation of native NC over a true gigabit network was negligible, about the same as running it in a VM with a virtual disk or a shared disk, i.e. about 10%. Using a virtual NIC caused NC to go from about 8:14 to 18:37 and KVM to go from 7:42 to 38:36. Regardless of the source of the IO performance problems, the effect was dramatic which is why I'm assuming that it's disk IO that's XP's problem. However I'm willing to concede that this is just a guess, it could be any number of other factors as many posters have pointed out. My original point was that if you are going to shell out for an expensive simulator like NC, VCS or Questa, you shouldn't cripple it by running on Windows.
Reply by ●June 20, 20082008-06-20
On Fri, 20 Jun 2008 10:16:22 -0700, Stephen Williams wrote:> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > General Schvantzkopf wrote: > | I haven't been able to get Icarus to work, it's not complete enough to > | run any of our testbenches. We aren't doing anything fancy, in fact > all | of our code is strict Verilog 95 it's not even 2001. > > Current snapshots are much improved, and bug reports are welcomed. > > - -- > Steve Williams "The woods are lovely, dark and deep. > steve at icarus.com But I have promises to keep, > http://www.icarus.com and lines to code before I sleep, > http://www.picturel.com And lines to code before I sleep." > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v2.0.4-svn0 (GNU/Linux) Comment: Using GnuPG with SUSE - > http://enigmail.mozdev.org > > iD8DBQFIW+XmrPt1Sc2b3ikRAtL9AKCykWIDYFWQkNqwfjcAJUgXewEa0wCgxqwt > 6U/NtBgPoBg4Y7aF5Ki6NsY= > =YODt > -----END PGP SIGNATURE-----I used the version that was in the F9 repositories which is 0.9, are the current snapshots significantly better than that one?
Reply by ●June 20, 20082008-06-20
On Jun 20, 11:21 am, General Schvantzkopf <schvantzk...@yahoo.com> wrote:> Regardless of the source of the IO performance problems, the > effect was dramatic which is why I'm assuming that it's disk IO that's > XP's problem. However I'm willing to concede that this is just a guess, > it could be any number of other factors as many posters have pointed out. > My original point was that if you are going to shell out for an expensive > simulator like NC, VCS or Questa, you shouldn't cripple it by running on > Windows.My tests indicate that the virtual memory manager in windows causes large simulations to run at 10% of the speed of a Linux/Unix/Solaris box. Which validates your original point. G.
Reply by ●June 21, 20082008-06-21
General Schvantzkopf <schvantzkopf@yahoo.com> writes:> times as fast on Linux as it does on XP. I'm pretty sure that the time > difference can be attributed to the performance of the Linux file system > (EXT3) vs the XP file system (NTFS). The real purpose of my investigationBut simulations are not file system IO bound unless your dumping trace files to the disk. You typically load the simulation image into memory and run (unless you're dumping waveform data to the disk). Petter -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?
