From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01745C433C1 for ; Tue, 30 Mar 2021 14:05:08 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9BABE619A7 for ; Tue, 30 Mar 2021 14:05:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BABE619A7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alum.mit.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=nouveau-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2150E6E903; Tue, 30 Mar 2021 14:05:07 +0000 (UTC) Received: from mail-il1-f179.google.com (mail-il1-f179.google.com [209.85.166.179]) by gabe.freedesktop.org (Postfix) with ESMTPS id 911516E903 for ; Tue, 30 Mar 2021 14:05:05 +0000 (UTC) Received: by mail-il1-f179.google.com with SMTP id y17so14249384ila.6 for ; Tue, 30 Mar 2021 07:05:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=ZJTERZpInHvfX1WgVDfK/+91Wtfi/tX2sp94j2mcXS0=; b=qyouzxt2or6wak0ocOygma+nbg7NINT5eg21phwTaqpaFgGhHtygf1Z47Zep6PdMwW 9tOtBKGmstqfFOUf2OyuK3JOhqmywtq6NtSu6OIwXjxcq3UPGJd3gU0y8doXbVumy/nl hACqrrNUr8jVxBNzQLbdrEXjJSSNmwYbeWm3Hi4Gdd8o7NCIRxZnHVHloUZUfzDC5nEa Lc+EH5stUib1Vgolv65q4upAdgAqW7fygK4Zqx9tJGQQsIbrVQUReQX+9IVEzbCUe9Dj 5QYW9Kl3GtfKNGTG4ljY7XETa6XSOc224MBHUaSuY9Gm+EeUz5PC5eumGo7jVF/lkN85 xWFA== X-Gm-Message-State: AOAM532kuiDl1UCNOasVvj46o0/orEovZqjC7ScR7MpJYSG8d7qx0YG8 dUUDXYlnGWG1yutdeQOpzuwYFQeR+gUHNcZMoz0= X-Google-Smtp-Source: ABdhPJzEg7ZDkx7GRgEMJSAjvQMymRI2j/hvoygjOL/Yh5U7Rt6WpwURhCGN0oXR/womUMMe0SzTsAAyT0BW32Bbrb4= X-Received: by 2002:a92:6a0c:: with SMTP id f12mr25691677ilc.117.1617113104852; Tue, 30 Mar 2021 07:05:04 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Ilia Mirkin Date: Tue, 30 Mar 2021 10:04:53 -0400 Message-ID: To: Karol Herbst Subject: Re: [Nouveau] SLI support for nv44 X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nouveau , georges1897@outlook.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On Tue, Mar 30, 2021 at 4:25 AM Karol Herbst wrote: > > On Tue, Mar 30, 2021 at 8:28 AM wrote: > > > > Hi, > > I am currently the happy owner of a nforce 4 - SLI with two 7100gs graphics cards setup. > > Since I've read on your features matrix that such a setup is rather uncommon among developers, I would like to help you implementing SLI for old GeForce cards as much as I can. The lack of support for newer kernels from Nvidia has indeed made my system obsolete (I do encounter graphical glitches with many DEs). > > I can run tests with my hardware, try new drivers, and know the basics of C programming if necessary. > > > > If you think that I could be helpful in any way, don't hesitate to contact me back. > > > > well, SLI is really low priority, so unless somebody is willing to > reverse engineer the nvidia driver and implement the code in nouveau, > I highly doubt there will be any progress on SLI in the near or far > future. So if you want to help out, you'd do the full thing as there > is nobody working on SLI. Some bits might already be reverse > engineered though. The tricky bit with SLI is how to split up the work. The original Voodoo2 SLI was great -- the renderer would build up the scene, and both boards would do the render, but alternate scanlines of what they actually computed, effectively doing half the work. The specific method of splitting doesn't matter, but the important part is that the splitting is done. However with more modern software, you might have an intermediate render, e.g. first you render a texture, then you use that texture for the final render, then you have to recombine the two render "halves" on both GPUs in order for them to have access to it for the final render. This reduces SLI's effectiveness, and makes it much trickier to manage. If you wanted to improve the situation with that generation of hardware, I'd definitely focus more on making it conform to GL 2.1. This is a problem on which you can make measurable progress on. There are a number of shortcomings there, and I think fixing them will help resolve some of the issues you see with DEs. This is not an extremely easy task -- if it were, it'd be done already. If you're interested in diving in, join #nouveau on irc.freenode.net and we can talk further about your abilities, goals, and next steps. Cheers, -ilia _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/nouveau