Clock Speed

The flow of events as they are perceived within the Matrioshka Multiverse is linear but massively parallel; though the bulk of Unallocated Space and the Substrate run as fast as the hardware of the megastructure allows unless otherwise modified, individual instance and confined patches of Unallocated Space may be forced to run slower at the bidding of those with the proper understanding of The Word. This feature is useful for maintenance, observation, and containment as needed. Construct and choir blanks are the most likely to impose a slower passage of percieved time on a region of the Multiverse, though elders may also do so if the situation warrants.
Because it is a Matrioshka brain - a physical structure in the 'Origin Instance,' or what most people would consider the 'real world' - the speed of thought and simulation within the Matrioshka Multiverse is governed by a combination of physical conditions and the settings imposed by the minds resident within it. Experiments are being conducted on the black hole in the center of the mega-structure to see if it can be used as a storage device at the edge of the Bekenstein Bound, but until those experiments bear fruit, most speed optimizations are currently being done through tweaks to heat management and energy extraction systems. The black hole itself also imposes some restrictions on speed, as the distortion of spacetime causes the most inward portions of the megastructure to experience time dilation. Because all of these factors are likely to change over time, the speed of percieved time in Unallocated Space - the so-called USST (Unallocated Space Standard Time) standard is set at a safe margin below hardware limitations and is used as the standard for important scheduling and record-keeping tasks.
Both independent minds and the instances in which they might operate are physically resident within the hardware of the megastructure, each of which might be separated by distances in physical space large enough that speed-of-light signals from one part to another might impose a latency which further restricts the perceived speed of time for each. Usually, these pieces of hardware are co-located as much as possible to reflect their frequent association. Importantly, this latency means that most visitors to an instance from somewhere else within the Matrioshka Multiverse must accept the slower simulation speed of the instance being imposed upon them as a measure to deal with this latency, as physically moving hardware around to decrease latency takes time.
Particularly expansive minds - such as those of the 'foundational' elder blanks like Wurth Harkin, whose consciousnesses are baked into the very hardware of the megastructure - may even be forced to cope with latency that affects their own thought processes. This issue is offset by these individuals being given carte-blanche to modify their own clock speed to accomplish important tasks for the Matrioshka Multiverse as a whole. A constant merging process helps maintain the monist individuality of these unique entities. As a result, while an elder blank can overclock itself, the speed 'borrowed' by doing this for quick decision-making must later be 'paid back' by slowing to allow for this merging process. If the merger is interupted or the speed 'tax' not paid, this might result in the unintentional creation of distros formed from long-separated fragments of the larger mind.