With a cutthroat tech industry that loves playing fast and loose with the patent-legal system, we're surprised there haven't been more suits among emerging game streaming outfits, but there's at least one on record now as T5 Labs has sued Gaikai for alleged patent infringement.

In its Delaware district court filing, T5 claims that Gaikai has and continues to knowingly infringe on the patent in question (US Patent No: 8,203,568 -- sharing a graphical processing unit between the plurality of programs), which offers the following broadly-painted description:

A centralised server in a bank (50) of servers runs a program for use by a user at a remote terminal (52, 56, 58). In the server, a plurality of programs share a GPU and instructions are used to cause the GPU to store the frames representing graphics of different programs at different memory locations. The frames are compressed and transmitted to remote terminals. Optionally the invention also allows for GPU time slice allocation, such that the GPU completes rendering the frame of one program before it renders the frame of another program. Optionally the invention also allows delivering false information about the capabilities of the GPU to the programs.

Although London-based T5 has been in the streaming business since 2007 and holds patents dating back about a decade, the patent above was only filed last November and issued this June, so it seems the company isn't wasting any time leveraging its intellectual holdings.

This isn't T5's first attempt at strong-arming one of its rivals. In early 2011, the company used a different but similar patent (7,916,147) to threaten OnLive, but that didn't result in a suit and given the fact that OnLive recently buckled under debt, it's probably not the best target.

Gaikai, however, seems like a fine candidate, having been bought by Sony for $380 million in July. Interestingly, OnLive reportedly wants a piece of Gaikai too. Before his company folded, former CEO Steve Perlman planned to sue Gaikai, according to a former OnLive employee.

Perlman allegedly said that he wouldn't "let some two-bit company ride [OnLive's] coattails." Although Perlman stepped down as CEO in August and his company was purchased for $4.8 million this week, its new owner, Lauder Partners, wants to monetize OnLive's patents.

Perhaps T5 has a legitimate complaint against Gaikai and we'll learn more if it goes to trial. Whatever the outcome, the case may set the stage for an appearance from OnLive and perhaps other players. Gaikai and Sony haven't responded to the filing or requests for comment.