On Wed, May 10, 2023 at 11:12:44AM -0400, D. Hugh Redelmeier via talk wrote:

This is an M75s gen 2 SFF unit. I installed the DIMMs and then could not replace the tray with 2.5" and 3.5" bays. It bottomed out on the DIMMs.

I suspect that the DIMMs themselves would fit but their flamboyant heat spreaders would not. The heat spreaders had stickers saying "warranty void if removed" so I didn't want to try. I have no idea how important heat spreaders are for RAM.

Oh OK. Yeah the ones crucial was selling had no such nonsense on them. They are just regular DDR4 DIMMs. So it does not need low profile, it just needs normal sized.

Speaking of which, the NVMe drives I buy come without heat sinks. Are they important? My guess: perhaps for NVMe gen 4 because they seem to take considerably more power.

Some of the faster NVMe drives can get hot, especially when writing, and if they get too hot they tend to throttle and loose speed, so the heatsink can help keep the performance up. Of course with normal use you probably aren't accessing it that much so it probably doesn't matter that much.

If heatsinks are needed, why don't they come with the drives? Are they supposed to come with the motherboard?

It varies. Some motherboards include them, some don't, some drives do, some don't. Of course a heatsink from a drive might not even fit with a certain board or case, depending on the size and shape.

In the case of the M75s, the NVe mounting kit that I cannot get from Lenovo does include a heat sink. <https://www.lenovo.com/ca/en/p/accessories-and-software/thinkcentre-and-thinkstation/thinkcentre-and-thinkstation-hard-drives/4xf1c39743>

There is no such heat sink in the M75q.

I suppose the case being so small they figure having a heatsink to help cool the drive is a good idea.

I may well be misremembering the number. Perhaps it was $200 for each of the two 32MiB SDRAM DIMMs. Or even some other price. It was probably early fall in 1997, but I'm not sure. (It was before Win 98 was released.)

Yeah I am thinking February of 1997. $200 each could have made sense unless ram prices took a dive in 1997. I don't remember.

I do remember 64M being extravagant at the time. I bought it with two 32MiB SDRAM DIMMs I think the motherboard was an Asus TX97. That used an Intel TX chipset. The TX had a limitation that it could not cache more than 64M of physical memory. The CPU was an AMD K6 200 or 233.

Yeah I was working with my dad's new PPro 200 at the time. It was his CAD system, and it was maxed out.

It was a while before I switched over to the K6/Linux box from the SPARCClassic. Solaris was still better than Linux and the Sun's display was better. The PC's CPU was a lot faster -- 200MHz vs 32Mhz.

At that time, "workstations" were still a higher tier than PCs. PC stores didn't understand workstation users. But there was almost no remaining technical reason so this disappeared fairly quickly. Linux was one of the factors. It is hard to remember how bad the PC display situation was compared with workstations.

I thought PCs were able to have pretty decent displays, but they were not cheap. We used a 20" Mitsubishi Diamond Pro 20 with a 486DX2-66 which managed 1280x1024@60Hz, which was then replaced with the PPro 200 with a 21" Hitachi CM803U in 1997. 1600x1200@85Hz seemed quite acceptable. The 486 ran a Mach32 2MB VLB card, the PPro was a Rage II 8MB PCI card. There was a 486DX50 before that with a #9 GXi Level 25 video card (2MB VRAM + 1MB DRAM ISA card with a TI34020 processor on it), but it was stolen and the other 486 was the replacement. The #9 card was displaylist based, which gave some amazing performance even though it was ISA. The software just sent commands to the card, and you kept the actual data in the DRAM on the card and the TI chip executed the commands to generate the framebuffer. Where machines with standard Trident or other VGA cards would need seconds to do a refresh in a CAD program, this thing took miliseconds since the card did all the line drawing and scaling. It was also able to implement the entire GDI stack of windows 3.1, so all window drawing, text rendering, fills, etc, were all done in hardware. Video playback is what killed TIGA since tat required transfering new framebuffer data all the time, and ISA was no good for that. And I have no idea why I can still remember all that crap. :) -- Len Sorensen

On Fri, May 12, 2023 at 06:31:47PM -0400, D. Hugh Redelmeier via talk wrote:

| From: D. Hugh Redelmeier via talk <talk@gtalug.org>

| So this is what I bought for $159.99: | <https://www.canadacomputers.com/product_info.php?cPath=24_311_1326&item_id=195989>

Surprise: The ThinkCentre M75s gen 2 SFF seems this RAM as DDR-2400!

Why???

Even though it is advertised as DDR-3200, when you read the specifications, it will only run at 3200 under XMP.

<https://www.kingston.com/datasheets/KF432C16BBK2_64.pdf>

FACTORY TIMING PARAMETERS • Default (JEDEC): DDR4-2400 CL17-17-17 @ 1.2V • XMP Profile #1: DDR4-3200 CL16-20-20 @ 1.35V • XMP Profile #2: DDR4-3000 CL16-19-19 @ 1.35V

XMP is an Intel "standard" and cannot be used by AMD systems (like the M75s).

There are hacks for AMD. For example Asus' DOCP. But a business computer line like the ThinkCentre is unlikely to use that.

Now I have to return a second set of RAM. Canada Computer might not be as accomodating as Amazon.

I wonder how one searcsh for "DDR-3200 RAM, no REALLY DDR-3200 RAM".

Good question. I think one needs to somehow find ram that is 3200 and 1.2V explicitly. The ones using XMP profiles seem to be 1.35V at that speed. This for example looks right: https://www.amazon.ca/Crucial-2x16GB-Desktop-Memory-CT2K16G4DFRA32A/dp/B07ZL... I guess you hit the same problem as this review: https://www.amazon.com/review/R17NJ5JNV9HE4D/ -- Len Sorensen

On Sun, May 14, 2023 at 03:41:47PM -0400, Nicholas Krause via talk wrote:

XMP or a version is on AMD. The problem your running into is CPUs these days default to a certain Ram Speed. I'm not sure of what gen your on for the Thinkpad but googling default memory speed of gen X, where X is your gen should resolve that issue. If you need to go helper than you need XMP or the AMD version to go beyond the default speed. For sure,3200 is beyond that for memory with current gen.

Lenovo ships the machine with DDR4 3200 ram, and AMD lists that CPU as running DDR4 at up to 3200. The CPU/system supports 3200, but it only uses the JEDEC default profile, not XMP. -- Len Sorensen

| From: Nicholas Krause via talk <talk@gtalug.org> Thanks for thinking about my problem. | Yes, Hugh will run into problems then of getting that speed. The JEDEC default | profile is 2400mhz | from memory. Yes, that is true of the modules that I bought that claimed to be DDR4-3200. That is in fact what I said in the initial message. | Not sure how locked the Bios on his Thinkpad is. It seems that | lots of people are | reporting XMP enabling not being possible. I don't know why they would lock | that considering | RAM Speeds needing XMP for the full speed, for the last decade or so. This is a ThinkCentre M75s gen 2 Small Form Factor machine. It takes desktop DIMMs, not SODIMMs. XMP is an overclocking technology from Intel. One should not need overclocking the get the advertised speed. | Not to mention AMD chips like faster RAM up to 3200mhz from memory. There are | suppose to be | performance differences there as well. This seems like a very bad manufacturer | decision if | this is occurring with Lenovo Laptops. This is a bad decision of the RAM vendor: misleading advertising. The computer does drive DDR4 3200 RAM at 3200: it came with an 8GiB DIMM. Yes, AMD Ryzen processors have traditionally have clocked certain things (like the cache) at the same rate as the memory. That's why I don't want to settle for DDR4 2400. | Hugh, are you just using the ram for web browsing or multitasking? If that's | the case I don't | think the 800mhz bulk is going to be a big deal. It's up to you but Ryzen only | wants faster | ram when I checked for applications like databases, GPU programming e.t.c. So | if your fine | with the lower speed and I'm assuming that's the use case it should be | alright. Of course it will be alright: it is replacing a 9 year old computer which is still OK. But I want what I paid for. Your characterisation of workloads using high physical memory bandwidth is a bit odd.

I wrote this thread to 1. inform others of the traps I encountered 2. to whine about how some traps are created to advantage vendors but end up just making complexity that hurts everyone. The RAM market is not simple. There are several dimensions one needs to get right: - technology (eg. DDR4 vs DDR5) - socket (eg. DIMM vs SODIMM) - standard (eg. DDR4 is nailed down by JEDEC but XMP "goes beyond" that standard). This one really annoys me -- don't call it DDR4 and then headline claims rquiring XMP without calling that requirement out. - physical size (heat spreaders make some DIMMs too tall for my application; perhaps they can also become too thick) - ECC / no ECC. This one is easy: you never get ECC without paying for it, so it is usually clearly marked. But it is not always clear whether a computer supports ECC. Random Ryzen system support ECC (great!) but it depends on the motherboard and the vendors don't highlight this. - registered/unregistered. Only servers, with a large number of RAM sockets need this. You might accidentally buy such a system used / off lease. It is a bit mysterious. The reason is that each circuit has limited "fan-out"; registered memory boosts the amount of fan-out allowed. You might also find some old registered memory cheap and then find that you cannot use it. - latency. Lower is generally better. It is a bit complicated -- there are several latencies for a particular chip. I just look at the headline one. Marketing has made that complexity unnecessarily hard to navigate. Even a fairly knowledgeable consumer like me gets bitten by traps that should not be there. RAM is a commodity. You should not have to read spec sheets from manufacturers to discover if a module will work for you. You should be able to go to any vendor and easily see what RAM they offer that would work for you. Amazon isn't a bad way to buy memory. But it doesn't let you search for RAM of the type you need. Without selective search, there is a lot of slogging. And, as I've described, the listings are misleading. Other retailers are different but not clearly better. I've looked at Canada Computers, Memory Express, and NewEgg. ca.pcpartpicker.com doesn't get this completely right. A couple of RAM manufacturers have product selectors that help you a lot. Lennart pointed this out. But then you don't get the advantage of buying a commodity.

| From: Lennart Sorensen via talk <talk@gtalug.org> | https://www.crucial.com/compatible-upgrade-for/lenovo/thinkcentre-m75s-gen-2... | would certainly work. It is listed as compatible, it is 3200 DDR4, | it is 1.2V. No silly XMP profiles involved. So such memory does exist, | but it is not very common. Most ram just ups the voltage using XMP | profiles to get the higher speeds. You need really good chips to run | 3200 at 1.2V. Thanks. I wandered around from there. Next stop ca.pcpartpicker.com I cranked various parameters. The key ones: - speed: at least 2300 - voltage, min and max: 1.2 I got to <https://ca.pcpartpicker.com/products/memory/#ff=ddr4&b=ddr4&S=3200,8000&Z=8192001&E=0&sort=price&B=1200000000> I ignored the entries without prices -- I assumed that they would be hard to finde. The latencies were all the same. I chose <https://ca.pcpartpicker.com/product/Pkyqqs/crucial-64-gb-2-x-32-gb-ddr4-3200-memory-ct2k32g4dfd832a> That was the second cheapest but it was the cheapest from a vendor I have experience with -- in this case Amazon.ca. Amazon.ca would sell me one that had been returned for $10 less but I would always wonder why it had been returned. PCPartPicker.com might well have missed some options but I am really weary of the hunt.