I'm in the process of buying a new PC and intent on doing a lot of editing (HD quality) with kdenlive so good performance for that purpose is the main criterion. Since I think it would be quite useful, a laptop is not out of the question despite the higher cost. So far, I've concluded the following and maybe you can give me more advice:

- obviously a quad core and 4 GB at least but does AMD or Intel make much difference?
- nvidia, because of VDPAU and preferably Purevideo Feature Set C but I'm not sure which mobile GPUs support that, does anybody know of a list?

I'd like to preview on the fly with effects and thus I wonder whether it is feasible and if so how? Would a fast CPU and GPU suffice or would I have to be able to uncompress the clips? In the latter case, I wonder whether any suitable harddrive solution can be found for a laptop considering size and speed needed. An external one is no problem (i.e. I can live with needing a power outlet) but I must know how what kind in that case - eSATA? USB 3.0?

I think disk space and CPU should be your main priorities. Graphics card won't matter too much except when previewing video afaik.

I am absolutely happy with my (gaming) notebook from Clevo (Taiwanese manufacturer, assembled by resellers all over the world, like Sager (USA), HawkForce (Germany) and many others). The notebook can be usually be configured at the reseller and you can get a variety of dedicated graphic adapters. NVidia GTX260M, 280M, 285M, 330M and some ATI cards as well.

My config: Clevo W860CU, Intel i7 720M (or 720QM, it's all the same), 4 GB RAM (1333 MHz), 500 GB Harddisk (5400 rpm), NV GTX260M a bright and superb Full HD glare type display (15,6"), Intel 5100 a/b/g/n WLAN.

Using openSuse 11.2 (KDE) some features do not work from scratch or not (yet) at all:
- Bluetooth
- Panel brightness adjustment via hotkeys (but brightness can be set with hotkeys once on bootup while you are in GRUB). Adjustment works with Ubuntu 8.?? live CD using GNOME. Hope this will be fixed by newer versions of kernel and drivers in openSuse 11.3)
- SD card reader (a known bug has to be fixed for this, so it will be working somewhen - hoping for openSuse 11.3)

But the most important features are fine: Speed, Display, wireless connection and a keyboard with a separate number block.

I did not test Firewire or eSata ports. The cooling fans are audible permanently but they run in a quite low frequency that does not bother me - and I am sensitve. The speakers are a joke - no bass at all, I am using a headset: I do not disturb anybody and I have a good sound quality.

Rendering SD material to MPG4 takes about the same time the movie is - per pass. Using the threads=0 switch and h.264 codec you get the 8 threads working to 70-90% usage and come up to about 1.5 times the movie length for two passes. Maybe this will become better - I have read about an enhancement in the linux kernel, supporting automatic overclocking of the intel i-core series better - maybe there is currently no overclocking at all. If so, the rendering to MPG4 will significantly speed up (rendering in two threads at 2.8 GHz instead of 1.63 GHz). Loading a 12.5 minutes project using 95 of 450 SD clips takes about 2.5 minutes using one core (two threads) and gives you time surf or check eMails as if no other program is running.

The Full HD panel is perfect - you have a lot of space and using 3 video and 2 audio tracks you will be able to configure a large preview window. Internet browsing (and reading here) is also no problem.

If you are looking for a well featured notebook, Sony Vaio F-Series (F11 Z or F12 Z) is an option, but in other hardware forums lots of user complain about noisy, high frequency fans and temperature problems (Sony called back 64.000 notebooks). The Sony has a 16.4" FHD display.

AMD or Intel? The mobile quadcores from intel have a much better performance but a higher TDP. Just read a test today with a AMD X4 (2 GHz) processor which is about as fast as the intel i5 dual cores (2,4 GHz with overclocking). The i5 series is slower than the i7 720M, so currently my first deal would be an intel i7 720. The i7 820M is much more expensive and has (only) a 10% better performance. Intel released a new i Series some days ago, they are now 740M and 840M - the technology is identical to the *20M series, but the ground frequency has been raised by 0.173 GHz. If you want to compare the CPU, maybe you want to look here: http://www.notebookcheck.com/Mobile-Prozessoren-Benchmarkliste.1809.0.html (German only, check the "Nur Notebook CPU's anzeigen" radio button to see notebook cpus only).

Maybe this helps. :) Cheers

I think I've found a relatively good store to buy a custom notebook from (they ship to Europe): http://www.mycizmo.com/

So I think I can get one with a sufficient CPU and RAM but which would you prioritize? I read that adobe premiere benefits significantly from 12 gb ram but how about kdenlive?

The more difficult question is the harddrive. Would one solid state drive be better than raid 5 (despite the recommendations here for professional use)?

This all depends on what my workflow will be. Preferably, I'd just plug in the camera and do the work and it seems to me that kdenlive now works with mine (a panasonic hdc-tm300) but my current pc is too slow for hd so I can't be sure (it's jerky as hell but no errors). So would that do with one SSD or should I go for a raid 5? Although, based on what I've read elsewhere, not even raid 5 suffices, if you work with raw HD video...

The Cx15i from your store is a W860CU from Clevo.

RAM: 4 GB is enough for Kdenlive. ddennedy stated that 1 GB is enough. So, working with a big project fills linux' buffers but used RAM is never over 1 GB. I decided for four because 8 (which is max for W860CU, so you'll have the 17.3" version I guess) are quite expensive. So I'll wait until the prices drop and add some mor 4 GB for buffering.

Solid state disk: For Kdenlive you will not need the speed. I thought about a 7200 rpm disk and took the 5400 which is more silent and writes about 60-80 MBytes per second. Kdenlive does render about 1000-2000 KByte a second, so from that point of view you'll never have a HD being the bottleneck.

I think you'll be happy with any system you buy - with 4 or 12 Gig of RAM and "slow" but big HD or SSD. Maybe you would like to save some money for a second camera. ;-)

Cheers

So I can expect to be able to preview HD on the fly even if I have some effects etc.? I mean, does yours suffice for previewing like that?

I think I'll settle for a relatively small HD if AVCHD doesn't need to be uncompressed with those specs. External USB HDs will then be a cheap way to add more space as I need it.

Here are a few recommendations :

1 - Get a nvdia graphics card, which support VDPAU for hardware decoding of AVCHD (and other codecs too). Personnaly I have an ATI, so I haven't been able to test, but it should work.

2 - Get a powerful CPU, with lots of cores, which will make the encoding times a lot smaller

3 - Get an very large HD (or two), and always convert your AVCHD files to DNxHD (the transcode feature of Kdenlive, in the file menu, works just fine).

Even with a powerful CPU, you will have problems editing AVCHD. I have a quad-core AMD Athlon X4 630 at 2.8 Ghz, and even though I can read AVCHD fine, editing is another matter, with big problems when seeking through files. DNxHD, on the other hand, is perfectly fluid, but it takes up about 5 times more HD space.

So when you start a project, the first thing you do is transcode all the video, files, taking a huge amount of HD space, which should take maybe a few hours max, depending on your CPU and the amount of data. So CPU + HD is really the most important (and an nvidia card should be worth having).

DNxHD is amazing. I can edit 1080p video like a champ on my Core2Duo but I can't even play 1080p h264 videos.

Short update on Intel TurboBoost under Linux: TB is available with kernel 2.6.33-rc5 or newer.