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Get access to the Rybka Cluster
Under the Rybka Cluster Rental Program, anyone can purchase time on the Rybka Cluster in continuous chunks of at least 48 hours. Customers receive client software as well as personalized account information and then use this software and account information to connect to the cluster from anywhere and at any time during their paid-for rental period. When a customer is logged in, the cluster presents itself on his client computer as a standard (UCI) chess engine, which can be installed and used in any standard chess GUI.


The Rybka Cluster includes all of the standard features expected of a chess engine, such as multi-variation analysis, exclude-moves analysis, pondering, full state reset, game play supporting all possible time controls, and so on. All 4-man and 5-man tablebases as well as selected 6-man tablebases are installed.

The Rybka Cluster is also robust to the various connectivity problems which clients can experience. When a client loses his internet connection, the last analysis he requested continues to run, and when he reconnects the accumulated analysis is automatically made available to him.

Finally, the Rybka Cluster has a highly developed and fully configurable notion of draw avoidance. This is useful in computer chess tournaments, to make sure that the cluster's ultra-deep searches don't result in overly cautious moves leading to too many draws. Our clients have also found the feature useful for preparing opening variations which may be objectively equal but which yield good practical winning chances.


There are no restrictions on what a customer can do with his or her Rybka Cluster time. Customers are welcome to use the Rybka Cluster for their own private chess analysis or automated game play, or to share their Rybka Cluster time with others, either informally or for profit.


Two standard, well-tested Rybka Cluster configurations are available starting February 1, 2011:

A Rybka Cluster 40 consists of 40 physical cores and can be rented for 238 Euro (incl. VAT) per day, or 200 Euro (without VAT) per day for customers outside the EU or businesses outside Germany. The minimum continuous Rybka Cluster 40 rental time is 5 days.

A Rybka Cluster 100 consists of 100 physical cores and can be rented for 595 Euro (incl. VAT) per day, or 500 Euro (without VAT) per day for customers outside the EU or businesses outside Germany. The minimum continuous Rybka Cluster 100 rental time is 2 days.

Custom configurations are also possible. Our current capacity is 296 physical cores, and this figure can be increased if necessary. Please don't hesitate to contact us about alternative possibilities if you are interested.


All aspects of Rybka Cluster rentals, including any discussions with us about the matter, will be treated as confidential by our team. Only Lukas Cimiotti and Vasik Rajlich will be privy to any such information.

Contact Us

Lukas Cimiotti is responsible for both the Rybka Cluster and the Rybka Cluster Rental Program. Time reservations and payment arrangements should be made directly with him. The preferred method for contacting Lukas is via private message at the Rybka Forum, addressed to the nick "Lukas Cimiotti". Impressum is here.

Long-Term Reservations

Rybka Cluster time is rented on a first-come first-served basis. We accept reservations for up to six months into the future, and recommend that you make important reservations safely in advance to guarantee availability. Whenever we upgrade our hardware, advance reservations will automatically be upgraded to configurations of equivalent value.

Alternative Rental Possibilities

The main limitation of the Rybka Cluster Rental Program is that cluster time must be reserved in advance and in continuous chunks of at least 48 hours. ChessBase GmbH and Convekta Ltd. are now working on solutions which will allow their customers to access the Rybka Cluster at any time without advance booking on a per-minute basis. We'll provide information about these possibilities when they become available.

Additionally, cheaper Rybka Cluster configurations of less than 40 physical cores will be made available later in 2011.


Time on the Rybka Cluster is offered as is. The Rybka Cluster has been extensively tested in a wide range of scenarios, but we make no warranties of any kind, either express or implied, including but not limited to the implied warranties of performance, merchantability, satisfaction, or fitness for a particular purpose.