Intel lost mobile and desktop share to AMD in Q1, according to IDC. Counter-intuitive, isn’t it? Depleted AMD inventories may explain at least some of the shift and selling low-end parts without making money might explain some more. IDC, by the way, also says that Intel gained share in PC servers and workstations.

Overall, IDC’s numbers give Intel 77.3% of the worldwide market, down 4.7%, to AMD’s 22.3%, up 4.6%. Interesting, considering that the European Commission is about to punish Intel for picking on AMD.

Shipments of the newfangled Atom chips that go into cheap netbooks dropped 33% sequentially, suggesting to IDC that OEMs had inventory. It calculates that Atom represented 21% of Intel’s Q1 mobile shipments and 6.5% of its mobile revenue.

It also calculates that Intel had 84.3% of the mobile market in Q1, down 4.7% with AMD at 15%, up 4.7%.

IDC’s numbers also show that Intel lost 3.9% of the desktop market finishing at 70% while AMD was up 3.8% to 29.8% while Intel’s share of PC servers and workstation increased 1.2% to 89.3%. AMD lost 1.2% for a total of 10.7%.

The number of processors shipped globally dropped 13% year-over-year. Sequentially – and there’s always a drop between Q4 and Q1 – shipments were off 10.9%, which wasn’t as bad as the really nasty drop from Q3 to Q4 of 17%.

That’s apparently why IDC thinks the market’s decline is slowing although it’s willing to bet that when it gets its numbers together Q2 shipments will decline again albeit modestly.

It says it’s “wary” that the demand it saw towards the end of the quarter and going into April was simply due to OEMs replenishing their inventories rather than reflecting a return of solid end demand and a return to market normalcy.

The revenues processors generated globally in Q1 dropped 25.1% year-over-year. And that’s 11% less than in Q4.

The numbers Mercury Research put out a week or so ago are similar to IDC’s.

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