From: lkcl <lkcl@web>
Date: Mon, 9 May 2022 18:17:54 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~2282
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=be344b80cdf4fb5939e6a14b5f4d484481978071;p=libreriscv.git

---

diff --git a/openpower/sv/SimpleV_rationale.mdwn b/openpower/sv/SimpleV_rationale.mdwn
index 65b6ff27b..3f84bcba0 100644
--- a/openpower/sv/SimpleV_rationale.mdwn
+++ b/openpower/sv/SimpleV_rationale.mdwn
@@ -45,7 +45,13 @@ the underlying 150 mhz bitcells), but these efforts are dwarfed by the
 two nearly three orders of magnitude increase in CPU horsepower
 over the same timeframe. Seymour
 Cray, from his amazing in-depth knowledge, predicted that the mismatch
-would become a serious limitation, over two decades ago.  Some systems
+would become a serious limitation, over two decades ago.
+
+The latency gap between that bitcell speed and the CPU speed can do nothing to help Random Access (unpredictable reads/writes). Cacheing helps only so
+much, but not with some types of workloads (FFTs are one of the worst)
+even though
+they are fully deterministic.
+Some systems
 at the time of writing are now approaching a *Gigabyte* of L4 Cache,
 by way of compensation, and as we know from experience even that will
 be considered inadequate in future.