From nobody Mon May 25 15:34:39 2026 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4gPKgr4LYdz6fPdZ for ; Mon, 25 May 2026 15:34:48 +0000 (UTC) (envelope-from olce@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R12" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4gPKgr3cwcz3rbJ; Mon, 25 May 2026 15:34:48 +0000 (UTC) (envelope-from olce@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1779723288; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ocekleWBT0vq79ImYplIR9xQcbFiT11HgKHTsYt5kik=; b=h+tV9A4T2vwa7jUygxjZlLQMCgIOW6XdOZNTBdkYD83V1b3MEPVq1+yFdbbkywohOF0B+A u0dovBQ5woByjYX6GOKO6PYj6D5XwngV3lvwAy0V3vAVp3jixDyMSm5Khm1A1HE5kTwfpq SFiAzG8F4rcbaSrfdqeJ+ymaIZq1HEnaNgPTdpchDdvIWqgKhZI5m8TunuACrnTFuBFegm LuxsKG9POS5OuCrSZW9Inqk3cXAV7O0LdG1sG52JHKxWgwsdDYNdCh8yeq0E0bBEbcBunn UyDLMc9BYQr77LRr4JY+sUUtj8rTd0DK2WrDoYTIvW6vr9Os9oMuMhXAp0JkNw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1779723288; a=rsa-sha256; cv=none; b=ec6MRXhHPagSKImWdThyXXK6iBgOfMnWAlA6p3T/P3qJWmAuQAP5+ycolB1ucKTLmdWQdI RbsxSYa6IDBKbPKLeAvgzvd6aD9v4QmUh6bT6u+Un8ZmP7OPQ7DtdqXaFFaZ1nX3I3VSZH tMCf4JMsnUyQLxTd5WHhdrvOFEHJGv8SEdeLJ3MYcB+/VRn84YlV81UZYRGBQkTw4CkAq9 /l8quOMYIf5KVenMf+2S8CLOnK9EBsn3WSki+68qRCln+thXmgM6VS+T/UVV4Kp2X4N4ug cGs1NXIx24h5LQYMJg4LdStpo1t4dNe4F7idb6sUCH3eN5TRbIl5a3Yq+8xITg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1779723288; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ocekleWBT0vq79ImYplIR9xQcbFiT11HgKHTsYt5kik=; b=Bv/tBXNLqNgGVDtMBVZiU35IZzPUjc7Mf7Bc6OgO+Ggqr4rlY83rFcv7OkpgELIOBrm/3V IxraGUynT8bIqHGlossm3wpt2WYK2EwjY+YfbPJ6Zd0YcWpEBV3pKfxnceH9bpYH+/1iep nWwucZEewwCf9rhI43RRVFIoM1QCyfpoEENLZ19R55WzecaDyO7FHCoMAxiXRJ9EHwG5Pg WHfyQUDEXkH6Y2BnpmKfwLqvb55OGPjfCaV3SEts0vVT+MVNxZnbbYnde8ZOYNIjxC86Ro bG8uxqQCcJ1aYjEO/jNw9E1CDGKwGFwC01pcGuZtzCyw63OY0qeMs0obpYdIcw== Received: from ravel.localnet (lfbn-nic-1-328-19.w90-116.abo.wanadoo.fr [90.116.162.19]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: olce/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 4gPKgq5W5lznSF; Mon, 25 May 2026 15:34:47 +0000 (UTC) (envelope-from olce@freebsd.org) From: Olivier Certner To: Chris Torek Cc: Warner Losh , Adrian Chadd , freebsd-current , ShengYi Hung Subject: Re: AMD, CPPC, etc Date: Mon, 25 May 2026 17:34:39 +0200 Message-ID: <11798552.X2hNYcAVgp@ravel> In-Reply-To: References: List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart11205534.1nsi24zuCt"; micalg="pgp-sha384"; protocol="application/pgp-signature" --nextPart11205534.1nsi24zuCt Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Olivier Certner To: Chris Torek Subject: Re: AMD, CPPC, etc Date: Mon, 25 May 2026 17:34:39 +0200 Message-ID: <11798552.X2hNYcAVgp@ravel> MIME-Version: 1.0 > On my desktop system, using 0 ("auto") mode works quite well: the > system idles around 80 to 95 watts, and when building ports or > /usr/src with all 32 CPUs going, gets up to the 320-watt range, all > without any OS work required. What's the EPP value you are using? The default of 0? Now, the question is: Do you get the same performance with these more power-flexible settings compared to the driver's defaults (which are desired performance set to maximum performance (which reported value do you see for that?) and EPP to 0) when building ports or src on the 32 cores? > I'm not sure what actually chooses the CPU frequency here. In auto-mode, the cores auto-tune themselves, so basically a hardware governor is at play. I suggest you forget about actual frequencies, CPPC can be finer-grained than that, with hardware leveraging other performance mechanisms, even if it seems that, currently, on AMD hardware, performance levels are achieved only through changing frequency. Regards. -- Olivier Certner --nextPart11205534.1nsi24zuCt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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