I have been using Premiere CS3 on a Dell Precision M2300 Laptop (dual core 2.2 Ghz with 4GB RAM and XP Pro) with external USB2 drives with NO PROBLEMS. Ok so I know that USB2 is not ideal, but to be honest for SD and the work that I have been doing it has always been absolutely fine. Everything has been responsive and there has been no problem with playback, editing for anything low/med load.

Now I have installed Premiere CS4, in fact I have completely wiped my system, done a light XP Pro install (i.e. nothing I don't need). I have even installed an eSata card and connected to an external eSATA drive (gives about 150Mbs due to cardbus limitations - yet still 3x faster than USB2/FW400).

IT IS TOTALLY UNUSABLE!!!

I cannot even play video properly without it getting clogged up, stalling, and 100% cpu for 20 secs. Then the interface does a painfully slow "modem like" redraw and freezes for 1 minute or so. Even if I turn the video channels off I find it struggles to do real-time scrubbing and editing of the audio.

I have not installed Vista as I can only put 4GB RAM in my laptop. However I feel that the XP route should still be acceptable. Do I need to by a new PC just to edit the same SD video as I have managed to do fine with CS3?

Looking at the spec on Adobe's web site it states that:

# 2GHz or faster processor for DV; 3.4GHz for HDV; dual 2.8GHz for HD*
# Microsoft® Windows® XP with Service Pack 2 (Service Pack 3 recommended) or Windows Vista® Home Premium, Business, Ultimate, or Enterprise with Service Pack 1 (certified for 32-bit Windows XP and 32-bit and 64-bit Windows Vista)
# 2GB of RAM
# 10GB of available hard-disk space for installation; additional free space required during installation (cannot install on flash-based storage devices)
# 1,280x900 display with OpenGL 2.0–compatible graphics card
# Dedicated 7200 RPM hard drive for DV and HDV editing; striped disk array storage (RAID 0) for HD; SCSI disk subsystem preferred

So how come it won't work ok on my set-up?

I can't help but think Adobe has shot itself in the foot here.

Premiere CS4 is a pile of bad code. BUT: I have tried PPro CS4 under Vista 64 today and am flabbergasted as to how much better it is under it compared to XP 32bít. The thing crawled with XP, but with Vista x64, it at least walks (with the same hardware)! Even window (panel ) resizing, which you accurately describe as modem-like refreshing, is GONE with Vista.

The same goes for After Effects CS4 - the project that took over 40 secs on XP (a very clean HP workstation) opens within 15 secs with Vista. I think Vita is better optimized for multicore than XP. I had almost never used my two cores to their full potential in XP (one of the cores was almost always idle, no matter how many apps I threw at it). Vista was designed with multicore in mind (heck, they didn`t even exist back in 2001). This goes to all the naysayers. Vista is mature after its three year run.

Hello.
The answer is yes.
According to Adobe, CS4 requires more computer and OS than CS3:

http://www.adobe.com/products/creativesuite/production/pdfs/cs4_production_premium_64bit_wp.pdf

I have tried PPro CS4 under Vista 64 today and am flabbergasted as to how much better it is under it compared to XP 32bít.

That is good news as I am currently looking into a new i7 system running Vista 64. What hardware are you running?

Hello.
The answer is yes.
According to Adobe, CS4 requires more computer and OS than CS3:

http://www.adobe.com/products/creativesuite/production/pdfs/cs4_production_premium_64bit_wp.pdf

That is a very interesting read. Adobe seriously need to update their spec listed Here (http://www.adobe.com/products/premiere/systemreqs/). As I am a Adobe Community Group Manager I think I might see if I can contact someone to sort this out. I can see a lot of people getting upset thinking that their machines should be ok.

My main workstation is a now-lowly HP XW4400 workstation with C2D 2,16 GHz, 4 GB RAM and ATI X1950 Pro 256 MB, nothing fancy. If I need realtime, which doesn't happen too often, I can use my Matrox RTX2, but most of the time, it's more pain than gain. I tend to move to Avid and FCP on my Mac, but CS4 is really more responsive under Vista 64 than under XP 32bit.

Make sure you read Jan Ozer's article mentioned in the PDF Manuel linked to. It's time to let go of XP after 8 years.

I installed CS4 - bought my system to it's knees. (Dell XPS1710 Laptop)

Uninstalled.

Reinstalled CS3.

Happy now! ;)