Same prob here Snodge. When I saw the new release I thought "hey that sounds cool". But after firing it up I dropped from about 30-40fps to about 5-10fps, so much for cool.
Anyway, I just went into prefs and turned off the shadows and it's back to normal again.
Nice idea LL, but totally unusable. Maybe I'll try it again on a later release if they say they've fixed it.
Here's my specs just for interest:
Tooly
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Second Life 2.7.1 (232828) Jun 14 2011 00:25:50 (Second Life Release)
Release Notes
CPU: Intel® Core2 Quad CPU Q6600 @ 2.40GHz (1600 MHz)
Memory: 3528 MB
OS Version: Linux 2.6.35.11-83.fc14.i686 #1 SMP Mon Feb 7 07:04:18 UTC 2011 i686
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce 8600 GT/PCI/SSE2
OpenGL Version: 3.3.0 NVIDIA 260.19.44
libcurl Version: libcurl/7.21.1 OpenSSL/1.0.0d zlib/1.2.5 c-ares/1.7.1
J2C Decoder Version: KDU v6.4.1
Audio Driver Version: OpenAL, version 1.1 ALSOFT 1.11.753 / OpenAL Community / OpenAL Soft: PulseAudio Software
Qt Webkit Version: 4.7.1 (version number hard-coded)
Voice Server Version: Not Connected
Built with GCC version 40103