As Lot's wife found out, looking back can be nasty and Q1 was very nasty for servers according to IDC.

Server revenue worldwide dropped 24.5% year-over-year to $9.9 billion in the first quarter, it says, the worst showing in the 12 years the researcher has been keeping count. It was also the third quarter of year-over-year revenue decline in a row.

Server unit shipments fell 26.5%, accelerating from a 12% drop in Q4, the largest ever year-over-year decline and the lowest quarterly server shipment total in five years.

Volume systems were hit the hardest, with revenues down 30.5%. Mid-range demand was down 13.6%, and high-end revenues fell 19.5%.

IDC said it was only the second time since 2002 that all three server segments experienced a year-over-year revenue decline in the same quarter.

IDC group VP Matt Eastwood said, "Market conditions worsened in all geographic regions during the first quarter as customers of all types pulled back on both new strategic IT projects and ongoing infrastructure refresh initiatives. Most enterprise organizations are deferring new IT procurements and instead focusing on extending server lifecycles and improving existing asset utilization."

However, he held out a ray of hope. "IDC believes that while these strategies are effective in the near-term, server demand will begin to improve in the second half of the year as customers begin to rebuild their IT capabilities in advance of a meaningful economic recovery in 2010."

IDC found HP and IBM in a statistical tie for first place in servers worldwide in Q1, each with 29.3%. HP lost 0.7 of a point and IBM gained 1.7 points complements of its mainframes and p systems. Dell was third with 11% of the market, its server revenues down 31.2% year-over-year. Sun's revenues were down 25.5%, translating into a 10.3% share. Fujitsu/Fujitsu-Siemens held onto fifth place with a 6.7% market share.

IDC said the market for non-x86 servers, your mission-critical RISC, EPIC and CISC systems, declined 19.4% to $4.8 billion. Q1 was the fifth consecutive quarter that non-x86 servers outperformed x86 servers. IBM maintained its leadership position, with 42.8% of the revenues, followed by HP (21.8%) and Sun (18.2%).

Unix revenues dropped 17.5%. IDC found "particular resilience" in the mid-range enterprise segment where worldwide Unix revenues were $3.3 billion, representing 33.1% of the quarterly server spend. IBM took first place with 31% of the money, followed by Sun (27.7%) and HP (27.7%).

IDC says IBM's z/OS-based mainframes outperformed the worldwide server market for the fifth consecutive quarter despite an 18.9% revenue decline to $889 million. They accounted for 9% of all server revenue in Q1, the highest first-quarter revenue share for System z in five years.

Windows server revenue was $3.7 billion down 28.9% or 37.3% of all server revenue in the quarter.

Linux server revenue worked out to 13.8% of all server revenue down 24.8% to $1.4 billion, its lowest level in five years.

The x86 server market worldwide dropped 28.8% to $5.1 billion on unit shipments down 26.3% to 1.4 million servers, the lowest x86 server revenue since 3Q03, with revenues at all of the top five vendors down 20% or more. HP led the market with 36.5% revenue share and Dell retained second place, with 21.4% revenue share.

IDC said it expects x86 systems to rebound faster than the overall market in the coming quarters.

Blade servers, including x86, Itanium and RISC blades, also decelerated sharply, recording negative growth for the first time. Factory revenue was down 14.4% on an 18.1% shipment decline. Overall, blades accounted for $1.1 billion or 11% of the quarter's server revenue. HP stayed number one with 52.2% of the market.

IDC said despite negative growth, the blade segment increased its share of revenue of the overall server market.

Although year-over-year Unix server revenue declined in the quarter, Unix servers represented a greater percent of the total IT spend in Q1: 33.1% versus 30.2% year-over-year.

IDC thinks that "lengthening server lifecycles in the data center, especially for scalable mid-range and high-end servers, affected Unix server sales, in terms of declining revenue and unit shipments in the first quarter. However, their strong contribution as a percent of first quarter worldwide server spend reflects the presence of mid-range and high-end systems carrying higher average sales prices, and the bifurcation of the market into low-cost and high-end systems, based on specific workloads, such as large corporate databases, transaction processing and business intelligence."