All of lore.kernel.org
 help / color / mirror / Atom feed
From: bugzilla-daemon@bugzilla.kernel.org
To: dri-devel@lists.freedesktop.org
Subject: [Bug 206351] RX 5600 XT Not Correctly Recognized, Max Memory Frequency Below Where it Should Be
Date: Fri, 31 Jan 2020 18:00:35 +0000	[thread overview]
Message-ID: <bug-206351-2300-wgPXT93MW1@https.bugzilla.kernel.org/> (raw)
In-Reply-To: <bug-206351-2300@https.bugzilla.kernel.org/>

https://bugzilla.kernel.org/show_bug.cgi?id=206351

--- Comment #6 from Alex Deucher (alexdeucher@gmail.com) ---
We expose the actual memory controller clock rate in Linux, not the effective
memory clock of the DRAMs.  To translate it, it follows the following formula:

Clock conversion (Mhz):
HBM: effective_memory_clock = memory_controller_clock * 1
G5:  effective_memory_clock = memory_controller_clock * 1
G6:  effective_memory_clock = memory_controller_clock * 2

DRAM data rate (MT/s):
HBM: effective_memory_clock * 2 = data_rate
G5:  effective_memory_clock * 4 = data_rate
G6:  effective_memory_clock * 8 = data_rate

Bandwidth (MB/s):
data_rate * vram_bit_width / 8 = memory_bandwidth

Some examples:
G5 on RX460:
memory_controller_clock = 1750 Mhz
effective_memory_clock = 1750 Mhz * 1 = 1750 Mhz
data rate = 1750 * 4 = 7000 MT/s
memory_bandwidth = 7000 * 128 bits / 8 = 112000 MB/s

G6 on RX5600:
memory_controller_clock = 900 Mhz
effective_memory_clock = 900 Mhz * 2 = 1800 Mhz
data rate = 1800 * 8 = 14400 MT/s
memory_bandwidth = 14400 * 192 bits / 8 = 345600 MB/s

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  parent reply	other threads:[~2020-01-31 18:00 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-30  9:24 [Bug 206351] New: RX 5600 XT Not Correctly Recognized, Max Memory Frequency Below Where it Should Be bugzilla-daemon
2020-01-30  9:31 ` [Bug 206351] " bugzilla-daemon
2020-01-30 18:12 ` bugzilla-daemon
2020-01-30 18:52 ` bugzilla-daemon
2020-01-30 21:21 ` bugzilla-daemon
2020-01-31  1:46 ` bugzilla-daemon
2020-01-31 18:00 ` bugzilla-daemon [this message]
2020-01-31 18:28 ` bugzilla-daemon
2020-01-31 19:26 ` bugzilla-daemon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-206351-2300-wgPXT93MW1@https.bugzilla.kernel.org/ \
    --to=bugzilla-daemon@bugzilla.kernel.org \
    --cc=dri-devel@lists.freedesktop.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.