Monthly Archive for May, 2011

Beast in sheep’s clothing: XFX HD 6850

About a month ago I was talking about how I wanted to get myself a new GPU, to get rid of that pathetic HD 5450. Well, I did, and I bought myself a nice XFX HD 6850. It was only £120 from eBuyer and came with a free copy of Shogun 2 (worth £29.99 on Steam), which seemed like a good deal (doubt I’ll ever play that game though). Came nicely next day (ordered on Fri, got on Sat). Installing was a breeze in the NSK2480 — although I had to remove my ATX, CPU and fan power cables temporarily to slot it in. Also had to remove my TBS6981, but with my issues with PVR, this isn’t a problem for the moment.

Why do I say it’s a beast in sheep’s clothing? Because of the overclocking potential. My card came with a default Core Clock of 775 Mhz (normally 750Mhz in other HD 6850 models), and a Memory Clock of 1000Mhz. That’s not shabby on it’s own, but I was able to clock it up to what was essentially equivalent of a HD 6870. Without any voltage changes, I managed to up it to a 900Mhz core clock and a 1150Mhz memory clock. GPU temps hit 73C at load. The reason this is achievable, is because the XFX HD 6850 uses a vapour chamber style cooling system, that will support the GPU core clock up to around 1Ghz. This requires significant voltage increases after the 920Mhz range. I could probably push the memory clock higher, but there’s no need, and 1200Mhz will definitely induce artifacting. Besides, the memory clock does not provide much of a performance compared to the core clock.

So don’t underestimate the HD 6850 as a card. It might seem on the weak side, but it sure has some over clocking potential. And I can get around 35FPS in Crysis maxed out with 8XAA.

That brought my WEI scores up, but seriously, do you need a 980X to get remotely near 7.9 for CPU? It would seem that the processor rating is the hardest to max out on WEI. Not that the scores are at all reflective of actual performance.

New Crystalbuntu update

A new, Crystalbuntu update has been pushed out. This is the first significant update since the first image, here are the main features that the update brings:

  • Faster boot times
  • More streamlined update service.
  • Quieter boots
  • Bug fixes

For a full list of changes, see the changelog at the bottom of the page here

Just restart your Apple TV to get this update immediately. XBMC will need to reinstall itself in a new location. Let me know how it goes, and consider making a donation to help fund future enhancements such as the aforementioned.

Why PVR support isn’t in the May Crystalbuntu update


If you’ve been following my Twitter, you will have seen me moaning about dependencies in the current master build of XBMC and the deprecation of Ubuntu 8.0.4 support. You will also have heard me mention I was including PVR support, but I have decided against offering nightly builds as the primary version of XBMC. PVR will be added to Crystalbuntu when it is part of a stable XBMC build. I decided this for the following reasons:

  • PVR branch is still experimental, and it is being tweaked at a phenomenal rate. It will be difficult to deploy frequent updates and track changes. The test product is not representative of the end.
  • PVR branch is buggy.
  • The current master uses a newer version of XBMC database. Offering this new version through an update would update MySQL and would stop all 10.1 Dharma clients on the network from using the DB unless they too were updated to nightlies, which is not fair to users. Downgrades wouldn’t fx this either — as the database wouldn’t have been fixed.
  • Difficulty in reverting to 10.1 Dharma

Therefore, I have not included a new XBMC build in the May update, however I have included a new update system. Read about the May update here

PVR:DVB in the UK: still not quite there

Getting a good PVR setup is annoying me lately. Virgin Media offer cable services over DVB-C but it is impossible to connect a device like the HDHomerun because of encryption. DVB-C cards will not work without a Conditional Access Module (which is likely not legal), not to mention the violation of TOS when you hook up equipment to their network that is not authorised. With flaky and quite frankly unappetising offerings on DVB-T (Freeview), and a lack of DVB-T2 cards back in June 2010, I took the DVB-s2 route. I’ve got a dual tuner TBS6981, and it works fine for playback / recording with Astra 28.2E.

Really, what I want though, is a nice integrated system with XBMC. MediaPortal does not play very nice. The channels seem to parse fine in the application, but the orders are unchangeable and are far from acceptable, as well as the issue with EPG information. Scrap that, I tried setting up a minimal Linux distro with XBMC and TvHeadend (fast boot off SSD I’ll tell you that). Unfortunately, recordings don’t seem to go into fstab mounted SMB shares, and the EPG listings reset constantly (I don’t want web-based listings, we get EPG data over DVB-S and I should be able to use it).

TVHeadend didn’t cut it. It insists on rescanning muxes every time, as well as purging its EPG listings on reboot. Once the dev resumes work in the summer, it might be good for a server box, but I was running this on an all rounder-machine, that is regularly rebooted. I did like the AJAX interface, which seemed a nicer touch compared to MediaPortal’s .NET system which seems to not use different threads for the UI and background processing, resulting in long periods of the UI thread locking while waiting for MP to query the remote database. MythTV and me haven’t got on that well before, but I guess I’ll be going back to try it now that I’m not using such a poor DVB-T aerial and I can actually get some decent SNR attenuation.