On Tue, Sep 19, 2023 at 5:43 AM Dale <rdalek1...@gmail.com> wrote: > > I been on Newegg using their rig builder feature. Just to get rough > ideas, I picked a AMD Ryzen 9 5900X 12-Core 3.7 GHz Socket AM4. Yea, I > did a copy and paste. lol It's a bit pricey but compared to my current > rig, I think it will run circles around it. My current rig has a AMD FX > -8350 Eight-Core Processor running at 4GHz or so. You think I'll see > some speed improvement or am I on the wrong track?
Lol - they'd be night and day, and that's just looking at CPU. The RAM is way faster too. CPU mark lists the 5900X as 6-7x faster, and the 7900X as almost 9x faster. > My problem is the mobo. I need a few PCIe slots. Most just don't have > enough. The trend is towards fewer slots. Some of that is driven by the addition of M.2 slots which require 4 lanes each. More of the IO is going to USB compared to PCIe, probably because that is what people tend to use with desktops. > Most have a slot for a video card. Then maybe 2 other slightly > slower ones and maybe one slow one. I can't recall what the names are > at the moment. I know the length of the connector tends to tell what > speed it is, tho some cheat and put long connectors but most of the > faster pins aren't used. This is actually pretty simple. PCIe is measured in lanes. There are no slower/faster pins. There are just lanes. A 4x slot has 4 lanes, and a 1x slot as 1 lane, and a 16x slot has 16 lanes. What you're talking about with "faster pins not being used" is something like a 16x slot with only 4 lanes wired. That behaves like a 4x slot, but lets you plug in physically larger cards. The missing 12 lanes aren't any faster than the 4 lanes that are wired, but obviously 4 lanes don't go as fast as 16 lanes. The other factor is PCIe generation. Each generation doubles the bandwidth, so a 1x PCIe v5 card with a supporting CPU is the same speed as a 16x PCIe v1 card. The interface runs at the maximum generation supported by both the card and the controller (located on the CPU these days). Most cards don't actually support recent generations - GPUs are the main ones that keep pace. I was talking about 10GbE NICs earlier, and if one supported a recent enough PCIe generation it could work fine in a 1x slot, but most use older generations and require a 4x slot or so. PCIe works fine if all the lanes aren't actually connected - you can plug a 16x GPU into a 1x riser, or a 1x slot that has an open notch on the end, and it will work fine. Though, in the latter case it will probably need physical support as the 16x slots have locks for large boards. The GPU will of course perform poorly with any kind of data transfer. > That confuses things. Anyway, mobo, which I > will likely change, CPU and memory is already adding up to about $600. If you're going to be spending THAT much on CPU+MB+RAM then I'd seriously look at how much moving to zen4 / AM5 costs. If you can get something cheap by going AM4 by all means do it, but if you aren't saving significant cash then you're buying into a much older platform. > I don't need much of a video card tho. Freeing up the 16x slot when you're so driven by PCIe requirements is a HUGE consideration here. > If someone knows of a good mobo, Gigabyte, ASUS preferred, that has > several PCIe slots, I'd like to know the model so I can check into it. I think you need to rethink your approach. Look, there is no reason you shouldn't be able to find a reasonably-priced motherboard that has lots of PCIe slots. If nothing else the manufacturer could stick a switch on the board, especially if you don't need PCIe v5 and don't mind the board switching the v5 lanes into a ton of v3-4 ones. However, nobody makes anything like that for consumers. There are chips out there that do some of that, but you'd have to custom-build something to use them. You really need to figure out how to get by with mostly 1x cards, and maybe 1-2 larger ones if you ditch the GPU. That is part of what drove me to distributed storage, and also using USB3 for large numbers of hard drives. PCs tend to have lots of unused USB3 capacity, and that works fine for spinning disks. It just looks ugly. (As a bonus the USB3 disks can often be obtained far cheaper.) -- Rich
