Here is a list of some of the top/good forums in the field of Computer Architecture ranked as A*, A, and B for CORE-ranking lovers. Note that CORE does not rank Computer Architecture conferences, faithfully. In fact, the two flagship conferences ISCA and MICRO are ranked A* (but wrongly with a field of research as Software Enginnering :)) and unranked computer software conference from 2020 (seriously?), respectively. There are conferences that are ranked below B and I have not included those forums here. The ranking is based on the quality of papers, expertise level of program (review) committees, review process (rebuttal/revisions), and acceptance rates. Papers that appear in top computer architecture forums are of length in the range of 12 to 14 pages. Note that, in computer science, conferences are more prestigious than journals and be aware of poor quality conferences with similar names :)
Flagship Conferences (A* for CORE-ranking lovers) in the field of Computer Architecture1. ISCA
Top conferences (A for CORE-ranking lovers) in the field of Computer Architecture1. PACT
Good conferences (B for CORE-ranking lovers) in the field of Computer Architecture1. ICCD
7. IEEE CAL (journal, competitive; top quality reviews; ranked B because of 4-page papers)
* DAC,ICCAD, and ICS are the flagship (A*) forums in the /DAC/CAD/super-computing area.
** SIGMETRICS and ASPLOS are inter-disciplinary conferences on computer systems.
For architecture security, S&P, USENIX SECURITY, CCS, and NDSS are the A* ranked conferences. HOST, RAID, European S&P, ACSAC, ESORICS are A ranked conferences. WOOT, HASP, and SEED are B ranked forums.