# Matrix assembly speed-up

Registered by
Anders Logg

Instead of computing and inserting the element tensor on each cell. We may compute the element tensor for a batch of elements in one single operation. This may potentially speedup both the element tensor computation and insertion.

In particular for tensor representation, the element tensors for a batch of elements may be computed using a single Level 3 BLAS call (dgemm).

This may require the addition of a new UFC function called tabulate_tensors.

## Blueprint information

- Status:
- Not started

- Approver:
- None

- Priority:
- Low

- Drafter:
- None

- Direction:
- Needs approval

- Assignee:
- None

- Definition:
- Discussion

- Series goal:
- None

- Implementation:
- Unknown

- Milestone target:
- None

- Started by

- Completed by

### Related branches

### Related bugs

### Sprints

### Whiteboard

GNW: A batch insertion function for matrices seems to have appeared in PETSc 3.2:

Fredrik V: I am in the progress of integrating MatSetValuesBatch with the PETScMatrix wrapper. That function only yields speedup on GPUs as far as I have understood from the PETSc team .

(?)