Yepp, that is too high. Try to check the thermal paste, never have to thick, and try to apply a good preasure on the CPU, not too hard, but equal over the whole die. I believe you should be able to get under 40C with standard settings...
The temperature sensors on most motherboards are fairly inaccurate for example a friend of mine was running a 2000+ XP in an MSI turbo2 motherboard which averaged 45 degrees normal operation and 50 under load. We recently upgraded his motherboard to an Epox 8k3A as he wanted to go DDR using the same CPU, heatsink and fan. We now average around 55 normal and 60 under load. His computer is running perfectly stable so the only explanation I can think of to why the CPU is averaging 10 degree higher temps is that the Epox 8k3a is estimating its temp differently to the previous motherboard. This makes sense when you take into account that the temperature increase under load is about 5 degrees exactly the same for both motherboards! I guess what I'm trying to say is as long as your computer is running stably and your temp doesn't fluctuate wildly you're probably ok.
Yes 70c is too hot, with a Volcano 7, you should be getting better temps than that.
Check the seating on the DIE, make sure its making good contact.
If you,re using thermal compound, and you should be, instead of the thermal pad, use Artic Silver III, and barely coat the DIE with an even layer, thinner than a sheet of notebook paper, do not gob it on, in this situation less is better, properly using Artic Silver III could lower your temps as much as 8c.
I know some people have run their machines at higher temps as stated, however I prefer my temps below 50c.
FYI 90c is the kill point for the AMD XP according to the AMD website.
Details, Details, Its all in the Details, If you need help, Don't leave out the Details.
Ive got a Palomino Athlon XP 1600+ @ 1.660Ghz (Close to 2000+ speeds) with a Volcano 7 and it NEVER goes above 44 Degrees celcious....i Also have a Thoroughbred Athlon XP 1800+ @ 2000+ speeds and it NEVER surpasses 34 Degrees Celcious also on a TT Volcano 7.........
Check ur setup.....i hope u didnt put Thermal Paste WITH the exisiting thermal pad on the bottom of ur heatsink cuz than that could be ur problem right there.....