From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 2A9A83BA8E for ; Tue, 27 Nov 2018 17:07:15 -0500 (EST) Received: by mail-wm1-x336.google.com with SMTP id g67so571280wmd.2 for ; Tue, 27 Nov 2018 14:07:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heistp.net; s=google; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=4c+68e66/LzQzxxn5GXLeCsf0tgDJtrKh0jowK0X2Xg=; b=ZN/yIr71vEA4PK3lhSC4elfarlPWcx63HQ2WlF6IOPX4SZY1TAqfyKAzD8BCSb/IcH 9d1yOwUjAklR7Z8H1InvnlnoNMnOMRhzH3KBs1GCyez6+CxWz0jr7YexS0sdbBSi0aio rnkHUOj39w50owWcF3c/x3j3kYLAiLdhLj0lt+ZNiGsIeB7QRAdbcYXLeDODkE5ATEeW FN05QP3Q9v9BskiMdWMDpMgn6BXGnkFCm0bFXAu1xQnZfY3SY1TmhiY/D+ddmsOVS4CF AiL9X4vYyqW8eIuclIKgMc9YcB0tO3uFrnhF6RrqQb9cLhD/2ZRslHY09L5HQ29bQPw/ 8T4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=4c+68e66/LzQzxxn5GXLeCsf0tgDJtrKh0jowK0X2Xg=; b=R4++9+ugZMfdNWYc88O4/nnwZJiUgT7K8x6ufmUxHwTzD4y2qNBpRz0/6kqGiRywQS itfxjh+7XjLBJ92pt2wdjMOVPmDITc7FGYxbAA1lDxN3CuEROXTMKxuVHhP2EGd8t9h7 v3ej1ZmRlbu0qhrKVLzsbbUBotgWWF7SlhGliZazhVLav3dnCdmaHjBpFHSR7xXmTY6Q T9pj0zonlNItFJ6W9LiknQzuGFa5/3C+CG21Nv4p9vXBJF6gkFua7Jhn1wQmcDtnDLtE pp296Fs/PMg6tA9aGc7WgwuzlQsCYxu6HA+6o2ScYDi6jbJITlbT9mNzUUWHBppq2Gvx VNNw== X-Gm-Message-State: AA+aEWYBLU1cS8OATY1NM4w6uLCHg3eakSnE3ph2Q0Vqh484G46wTRpZ Yu6q1nkigST7kz2YmWON0/FU6w== X-Google-Smtp-Source: AFSGD/WuLISngbX+GRNV4nEWsW1cnEMapp//zXRQHNb64nWPLXvM/RtxtPgn03RWx/oUztgvtNdG5w== X-Received: by 2002:a1c:9a46:: with SMTP id c67mr488922wme.21.1543356434224; Tue, 27 Nov 2018 14:07:14 -0800 (PST) Received: from tron.luk.heistp.net (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id g2sm5561266wrw.78.2018.11.27.14.07.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Nov 2018 14:07:13 -0800 (PST) From: Pete Heist Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_4A37846D-6A3E-4BF3-853D-89E61A4A5A38" Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Date: Tue, 27 Nov 2018 23:07:12 +0100 In-Reply-To: Cc: bloat To: Dave Taht References: <6C1479A8-43E8-4F89-BCEA-1D28CA3E8589@heistp.net> <87r2fbzrng.fsf@taht.net> <4FB37CD5-0DAB-479E-8C8C-671D442D668E@akamai.com> <20181127103114.3f403d8a@xeon-e3> X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Bloat] one benefit of turning off shaping + fq_codel X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Nov 2018 22:07:15 -0000 --Apple-Mail=_4A37846D-6A3E-4BF3-853D-89E61A4A5A38 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Nov 27, 2018, at 8:09 PM, Dave Taht wrote: >=20 > I wish I knew of a mailing list where I could get a definitive answer > on "modern problems with async circuits", or an update on the kind of > techniques the new AI chips were using to keep their power consumption > so low. I'll keep googling. I=E2=80=99d be interested in knowing this as well. This gives some = examples of async circuits: = https://web.stanford.edu/class/archive/ee/ee371/ee371.1066/lectures/lect_1= 2.pdf = Page 43, =E2=80=9CBottom Line=E2=80=9D mentions that asynchronous design = has =E2=80=9Csome delay matching / overhead issues=E2=80=9D. Apparently = delay matching means getting the signal outputs on two separate paths to = arrive at the same time(?) Presumably overhead refers to the 2x space on = the die previously mentioned, for completion detection. Pages 23-25 on = =E2=80=9Cdata-bundling constraints=E2=80=9D might also highlight some = other challenges. Some more current material would be interesting = though...= --Apple-Mail=_4A37846D-6A3E-4BF3-853D-89E61A4A5A38 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
On = Nov 27, 2018, at 8:09 PM, Dave Taht <dave.taht@gmail.com>= wrote:

I wish I knew = of a mailing list where I could get a definitive answer
on "modern problems with async = circuits", or an update on the kind of
techniques the new AI chips were using to keep their power = consumption
so low. I'll = keep googling.

I=E2=80=99d be interested in knowing this as = well. This gives some examples of async circuits: https://web.stanford.edu/class/archive/ee/ee371/ee371.1066/lect= ures/lect_12.pdf

Page 43, =E2=80=9CBottom Line=E2=80=9D mentions that = asynchronous design has =E2=80=9Csome delay matching / overhead = issues=E2=80=9D. Apparently delay matching means getting the signal = outputs on two separate paths to arrive at the same time(?) Presumably = overhead refers to the 2x space on the die previously mentioned, for = completion detection. Pages 23-25 on =E2=80=9Cdata-bundling = constraints=E2=80=9D might also highlight some other challenges. Some = more current material would be interesting though...
= --Apple-Mail=_4A37846D-6A3E-4BF3-853D-89E61A4A5A38--