Severe Time Drifting after Migration from 10.5.8 - Help!

Question

Hey everyone, I'm hoping someone can help me out or shed some light on a very odd issue that came about this morning.  I'm really having a hard time figuring out a fix.
I recently upgraded one of my old Mac mini servers to some new, (to me), hardware.  The old server was a last-gen G4, and the new one is a late 2006 Intel.
The migration went totally fine, and all services are responding and working as expected.  This server really isn't used for all that much, so I didn't anticipate any real issues in upgrading from 10.5.8 (PPC) to 10.6.7 (Intel).  But after checking everything over this afternoon, I landed on a really weird issue. 
I can literally watch the time progress slower on this server.  Really.  The seconds pass slower, and after about an hour, it will be up to five minutes behind all the other servers in my infrastruture.  The server is setup to watch time.apple.com as it's NTP, and there's no change with another NTP server.  I can grep the NTPd and it seems to be working fine.  I've "started fresh" by removing ntp.conf and ntp.drift, rebooted, and had NTPd recreate them after setting new time and date preferences.  That seems to have helped a *bit* but it's still persisting.  Time zone information is correct.  I've even turned off time sync altogether and it still persists, so it's got to be a local issue with the system.
Now, after some pondering, I believe I know what's causing the issue.  The person I inherited the server from replaced the stock 1.5 Core Solo with a 1.66 Core Duo, which I've seen done plenty of times before, and never heard any real issues with.  And I did physically check the upgrade, and everything seems to be perfect.  The system sees both cores fine, and everything is stable.  Except this very odd time/clock issue.  This is the only root cause that I can possibly think of for it doing this.
And what's odd, is that if the time is wrong in the menu bar, and I go into the Time and Date prefpane, it instantly updates to the right time. 
Now really, this isn't *that* big of a deal for this server.  None of it's services rely on perfect time, (Kerberos and whatnot), but it's still rather annoying, especially for Time Machine backups.  My main curiousity is if anyone knows how to increase the interval for NTP syncing with time.apple.com, so it'll check every hour or so, (I believe it checks every 12 by default.  Correct me if I'm wrong).
TL;DR
After migrating from Leopard Server (PPC) to Snow Leopard Server (Intel), my system clock is running about five minutes slow per hour.  Suspecting processor upgrade is to blame.  How can I increase NTP syncing interval with time.apple.com?
Thanks in advance everyone!

Answer 1

You can add/modify the minpoll and maxpoll values in ntp.conf.  This should allow you to set the time poll and reset a bit more aggressively.
The Xeon chips have been notorious for time skew.  I've not seen the same with CoreDuo and Core2Duo. 
You may also just want to periodically stop and start the NTP process.  This can be down using systemsetup command:  systemsetup -setusingnetworktime on/off
In corporate environments with Windows time servers that reboot frequently, I tend to automate a script that stops network time, waits a few seconds, and then starts it again.  This will force a sync.
Hope this helps.  Oh, and by the way, time is critically importation to Kerberos authentication and authorization from the client.  Next the DNS, time is the most common cause of access denial.  Keep DNS and time healthy.