Thanks, Bernd. I am trying to get TScale approved for testing as we speak! I have noticed odd affinities during running processes. Occasionally, we'll have an instance of an application that will set one "threads" floor at 30-40% proc. usage. The other 3 threads operate normally. For instance... thread 0, 2, and 3 will be at 37% proc. usage, while thread 1 is at 67%. It hasn't caused a problem, per se, but it does throw off the CPU numbers in perfmon and for one of my load evaluator rules. Kind Regards, Bob On Thu, 30 Sep 2004 12:18:07 -0400, Bernd Harzog <bernd.harzog@xxxxxxxxxxx> wrote: > Let me add some fuel to the fire. I do not know if this is pervasive, but I > have noticed on several customer systems. On a hyperthreaded dual, you have > processors 0,1,2 and 3. 0 and 1 are the "physical" processors, and 2 and 3 > are the virtual processors. These four processors DO NOT behave identically. > Specifically, the virtual processors seem to have severe problems with them > that can negatively the performance of the whole server. > > Here is what we have observed. TScale has a feature that allows you to set > the Affinity of a process. If you have an infrequently used process that > tends to go rogue, we recommend that you consider putting in a Priority rule > for that process to have its Priority be reduced when the process goes rogue, > and then also nailing all instances of that infrequently used process to one > of the N CPU's. That way, if two instances of that process are launched and > go rogue they can be isolated to one of the NT CPU's and set to low priority > so that they do not do damage to even that CPU. > > The problem that we observed is that when you set Priority rules in TScale > they typically take the form of "reduce Priority when processname.exe uses X% > CPU for more than N seconds". So, it might say, reduce the Priority of > Acread32.exe when it takes more than 20% of CPU for 20 seconds. The theory is > that it might validly need lots of CPU for 20 seconds, but if it is doing > more than that, it is a hog and steps need to be taken to make sure that it > does not harm other processes and users. > > Well what we discovered is that when a process is running on one of the > virtual CPU's (2 or 3) and goes rogue, it shuts down the whole server. So, if > something uses 25% of CPU (all of CPU 2 or 3) doing this on a virtual CPU on > Windows 2000 somehow clogs up the entire system. So, our recommendations > were; 1) don't use hyperthreading on Windows 2000, and if you insist upon > turning it on, don't use Affinity to assign any processes to the virtual > CPU's (only assign processes to the physical ones). > > I would be interested in knowing if anyone else has seen anything like this. > If you have, and you could share with the list that would be most useful. > > Best Regards, > > Bernd Harzog > CTO > RTO Software, Inc. > bernd.harzog@xxxxxxxxxxx > 678-455-5506 x701 > www.rtosoft.com > > > > -----Original Message----- > From: Brian Madden [mailto:brian@xxxxxxxxxxxxxxx] > Sent: Thursday, September 30, 2004 11:34 AM > To: thin@xxxxxxxxxxxxx > Subject: [THIN] Re: Hyperthreading > > The main problems in W2K with Hyperthreading are: > > (1) Stability. I haven't seen this personally, but it's something that > everyone says > (2) W2K doesn't realize that 4 hyperthreaded processors are really two > physical processors. The problem is that the system might try to "load > balance" some work evenly across processors 0 and 1, thinking it's doing > a good job but not realizing that they're really going to the same > place, all while procs 2 and 3 are sitting idle. Multiply this by > several billion ticks per second and it could in theory lead to worse > performance. > > Again, it's only a few percentage points, and if someone is gung-ho for > THE on W2K, I won't stand in their way. > > Brian > > Brian Madden > brian@xxxxxxxxxxxxxxx > +1.202.302.3657 > Sign up now for BriForum 2005: A 100% technical, 100% independent > server-based computing conference from April 11-12, 2005. Visit > www.briforum.com for details. > > -----Original Message----- > From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On > Behalf Of Bob > Sent: Thursday, September 30, 2004 10:57 AM > To: thin@xxxxxxxxxxxxx > Subject: [THIN] Re: Hyperthreading > > Thanks, Jim... great article on the benefits of HTE > > -but- > > Intel is criminally terse in their statement that it should be > disabled on Win2k. I can't tell if their rationale is functional or > political. I'm about to rock the boat here, and I'm going to be asked > tough questions. I'm hoping somebody will weigh in with some personal > trials. > > Thanks, > Bob > > ----- Original Message ----- > From: Jim Kenzig http://thethin.net <jimkenz@xxxxxxxxxxxxxx> > Date: Thu, 30 Sep 2004 07:06:52 -0700 (PDT) > Subject: [THIN] Re: Hyperthreading > To: thin@xxxxxxxxxxxxx > > See > http://www.2cpu.com/articles/42_1.html > http://thethin.net/faqs2.cfm?id=444&category=1&sortby=score > Leave it off for Win2K! > http://thethin.net/faqs2.cfm?id=443&category=1&sortby=score > > Regards, > Jim Kenzig > http://thin.net > > Bob <bobmails@xxxxxxxxx> wrote: > > Has anybody experimented with Hyperthreading On -vs- Off on Win2k > servers? I've heard rumblings that it can be problematic, and perhaps > decrease performance. I noticed that most SpecInt. winners have it > disabled. I'm considering disabling it on one of my farm servers to > observe the results. If anybody else has experimented I'd love to > hear about it. > > Thanks in advance, > Bob > ******************************************************** > This Weeks Sponsor RTO Software > Do you know which applications are abusing your CPU and memory? > Would you like to learn? -- Free for a limited time! > Get the RTO Performance Analyzer to quickly learn the applications, > users, > and time of day possible problems exist. > http://www.rtosoft.com/enter.asp?id=320 > ********************************************************** > Useful Thin Client Computing Links are a vailable at: > http://thin.net/links.cfm > *********************************************************** > For Archives, to Unsubscribe, Subscribe or > set Digest or Vacation mode use the below link: > http://thin.net/citrixlist.cfm > ******************************************************** > This Weeks Sponsor RTO Software > Do you know which applications are abusing your CPU and memory? > Would you like to learn? -- Free for a limited time! > Get the RTO Performance Analyzer to quickly learn the applications, > users, > and time of day possible problems exist. > http://www.rtosoft.com/enter.asp?id=320 > ********************************************************** > Useful Thin Client Computing Links are available at: > http://thin.net/links.cfm > *********************************************************** > For Archives, to Unsubscribe, Subscribe or > set Digest or Vacation mode use the below link: > http://thin.net/citrixlist.cfm > > ******************************************************** > This Weeks Sponsor RTO Software > Do you know which applications are abusing your CPU and memory? > Would you like to learn? -- Free for a limited time! > Get the RTO Performance Analyzer to quickly learn the applications, users, > and time of day possible problems exist. > http://www.rtosoft.com/enter.asp?id20 > ********************************************************** > Useful Thin Client Computing Links are available at: > http://thin.net/links.cfm > *********************************************************** > For Archives, to Unsubscribe, Subscribe or > set Digest or Vacation mode use the below link: > http://thin.net/citrixlist.cfm > > > > > ******************************************************** > This Weeks Sponsor RTO Software > Do you know which applications are abusing your CPU and memory? > Would you like to learn? -- Free for a limited time! > Get the RTO Performance Analyzer to quickly learn the applications, users, > and time of day possible problems exist. > http://www.rtosoft.com/enter.asp?id20 > ********************************************************** > Useful Thin Client Computing Links are available at: > http://thin.net/links.cfm > *********************************************************** > For Archives, to Unsubscribe, Subscribe or > set Digest or Vacation mode use the below link: > http://thin.net/citrixlist.cfm > ******************************************************** This Weeks Sponsor RTO Software Do you know which applications are abusing your CPU and memory? Would you like to learn? -- Free for a limited time! Get the RTO Performance Analyzer to quickly learn the applications, users, and time of day possible problems exist. http://www.rtosoft.com/enter.asp?id=320 ********************************************************** Useful Thin Client Computing Links are available at: http://thin.net/links.cfm *********************************************************** For Archives, to Unsubscribe, Subscribe or set Digest or Vacation mode use the below link: http://thin.net/citrixlist.cfm