RealVNC slowness (WinVNC)
James ''Wez'' Weatherall
Thu Jun 12 11:56:01 2003
Connection freezes are usually associated with a poor network connection -
either the ISDN line is shared by many people and starts dropping lots of
packets, or it's actually got a high bit error rate and causes TCP to drop
them, or worse, to corrupt the protocol stream. When it's not frozen, what
is the VNC session like?
On your PC, it's hard to say - the most likely cause is broken network
config or network card at one of the ends. It could also be a misconfigured
or old VNC installation on the Win98 box, but that seems unlikely. Which
versions of VNC are the client and server running in the two situations?
VNC obviously doesn't take 15 seconds to respond normally, otherwise we'd
have noticed and fixed it... :) I use VNC between a 2K box and an XP box on
a 50/50 wired/wireless LAN and it outperforms RDP noticably for most things.
Dr. James Weatherall
RealVNC Ltd. - http://www.realvnc.com
> -----Original Message-----
> From: ViNCe [mailto:email@example.com]
> Sent: 11 June 2003 22:11
> To: James ''Wez'' Weatherall; firstname.lastname@example.org
> Subject: RealVNC slowness (WinVNC)
> Importance: High
> i've got some strange problem here;
> when i'm working via the internet (from WinXP on ISDN => various Win (XP)
> this connection is already slow (with some systems, they 'freeze'
> for a min
> or 2)
> however, when i try to work on a PC (Win98) on my LAN (100mbit
> full duplex)
> i cannot do ANYthing without having to wait
> AT LEAST 15 seconds until the mouse responds !!
> does anyone have a solution, or a tip to get this working as fast as, for
> example (hey, don't shoot me) PCAnywhere or Windows Remote desktop?
> i don't care about more than 16 colors (256 would be nice), but
> it should be
> -----Oorspronkelijk bericht-----
> Van: email@example.com
> [mailto:firstname.lastname@example.org]Namens James ''Wez'' Weatherall
> Verzonden: woensdag 11 juni 2003 19:49
> Aan: email@example.com
> Onderwerp: Re: Another question about Cadence slowness
> The Tight encoding was superceded in VNC release 3.3.4,
> which introduced
> automatic encoding selection and the new ZRLE encoding. ZRLE provides
> similar compression ratios to Tight (better in many cases) with less
> processing overhead.
> Dr. James Weatherall
> RealVNC Ltd. - http://www.realvnc.com
> Jeff Boerio wrote:
> > Fred,
> > This is a problem we have observed as well. I'm sure you notice that
> > the CPU of your Windows VNC client goes through the roof as it attempts
> > to do things such as redraws. It is not a network issue at all, it is
> > in the Windows client itself.
> > I spent a lot of time working with the folks at Real VNC on this
> > problem, and you should see an dramatic improvement in their next
> > release.
> > - Jeff
> Hi, Jeff,
> I do recall reading in the archives that work was
> being done with RealVNC folks to deal with it. I
> don't recall if the exact CAD tool was mentioned.
> I don't suppose that the change in code could be
> easily incorporated into TightVNC? Tight encoding
> really helps sometimes, and I'm not sure why
> there hasn't been a merging of efforts.
> Fred Ma, firstname.lastname@example.org
> Carleton University, Dept. of Electronics
> 1125 Colonel By Drive, Ottawa, Ontario
> Canada, K1S 5B6
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