Just when I thought it was safe to shift away from my recent pre-occupation with InfiniBand (see the last three newsletters), it turns out that there are still more sharks swimming in the waters and gobbling up InfiniBand technology companies.Several InfiniBand companies have disappeared over the past year or so. While some have just plain gone away or have refocused their interests in other technology areas where they hope will bring profitability more quickly, connectivity is one important InfiniBand category where companies have been disappearing for another reason. When InfiniBand switch or adapter makers go away, more likely than not it is because some industry heavy-hitters have acquired them. The most obvious example of this occurred last April, when Cisco spent $250 million to buy Topspin.Topspin made fabric switches that provided connectivity between Fibre Channel, Gigabit Ethernet and InfiniBand. Cisco had made several storage-based acquisitions prior to this \u2013 most significantly, storage-area network switch builder Andiamo in 2002, wide area file services (WAFS) providers Actona in 2004, and FineGround in 2005 \u2013 but the Topspin purchase rounded out Cisco\u2019s portfolio and re-emphasized the company\u2019s seriousness about being a player in more than IP.Cisco now offers switches for IP, Fibre Channel over IP (FCIP), InfiniBand and Fibre Channel.After Cisco\u2019s Topspin purchase, it seemed like it would only be a matter of time until the other shoe would drop and storage-switch makers Brocade and McData would get on the InfiniBandwagon. And sure enough, last week the thud of a dropped shoe was there for everyone to hear, but when we turned around, we found out that the owner of the shoe was neither Brocade nor McData. InfiniBand technology firm PathScale had been purchased all right, but the acquisition was announced by\u2026 Qlogic!Qlogic of course has been a player in SANs since the beginning, and its Fibre Channel adapters are ubiquitous wherever you see Fibre Channel SANs. PathScale has two InfiniBand product lines: a 64-bit compiler suite and the InfiniPath family of host channel adapters (HCA). The HCAs seem to provide a good complement to the company\u2019s existing lines of adapters and controllers, but having a successful 64-bit compiler offering is clearly one of the best ways to build a formidable presence in high performance computing. $109 million may have bought Qlogic a lot of useful synergy.And what about Brocade and McData? Right now, when it comes to InfiniBand, both are non-players. Brocade several years ago mentioned that a new core switch (the Silkworm 12000) would have InfiniBand capability, but that has yet to happen.Which major InfiniBand companies are still independent? Leading the list are Mellanox and Voltaire. These two have several things in common: both show investment from top-level investors, both have additional investment from major storage and systems players, and both develop their technology in Israel. Watching these two will be interesting. What with the valuation placed on the Topspin and PathScale acquisitions, we can only wonder what is going through their investors\u2019 minds these days.