<div dir="auto"><div><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, May 20, 2019, 6:40 PM D. Hugh Redelmeier via talk <<a href="mailto:talk@gtalug.org" target="_blank" rel="noreferrer">talk@gtalug.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">| From: Russell Reiter via talk <<a href="mailto:talk@gtalug.org" rel="noreferrer noreferrer" target="_blank">talk@gtalug.org</a>><br>
<br>
| On Mon, May 20, 2019 at 11:42 AM D. Hugh Redelmeier via talk <<br>
| <a href="mailto:talk@gtalug.org" rel="noreferrer noreferrer" target="_blank">talk@gtalug.org</a>> wrote:<br>
<br>
| > Why do you think that this was heat-related? It might be, but that<br>
| > would not be my first guess. (I am not an expert on this.)<br>
| <br>
| Apparently, at least on Crucial products, there is built in thermal<br>
| monitoring which will throttle speeds.<br>
| <br>
| Here's a link to the 1TB Nvme. On sale for the next few days for $147.00,<br>
| about $40.00 less than I paid.<br>
| <br>
| <a href="https://m.newegg.ca/crucial-p1-1tb/p/N82E16820156199?item=N82E16820156199&m_ver=1" rel="noreferrer noreferrer noreferrer" target="_blank">https://m.newegg.ca/crucial-p1-1tb/p/N82E16820156199?item=N82E16820156199&m_ver=1</a><br>
| <br>
| Here's a link to a review of Crucial's Thermal Throttling capacities<br>
<br>
Wow, prices sure have dropped. (I wish I had more sockets that would<br>
take NVMe.)<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">It's the price drop which made me change my build plan. I was going to have just one SSD for boot and install xTB Sata disk drives. I tried out M.2 just because I could. 90$ (tax inc.) for 32gb seemed ok for fun. Then I put 250gb in slot 2 so I could run multiple versions of Fedora while I came to terms with learning about systemd and dealing with recent fencing in side channel attack mitigations. For the last year the z370 issued so many firmware updates, I stopped doing them til last month.</div><div dir="auto"><br></div><div dir="auto">However<span class="m_6395179228664172432money"><span class="money">$180.00</span> w tax</span> for 1TB was too good to pass up.</div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
| <a href="https://www.techpowerup.com/reviews/Crucial/P1_NVMe_M.2_SSD_1_TB/7.html" rel="noreferrer noreferrer noreferrer" target="_blank">https://www.techpowerup.com/reviews/Crucial/P1_NVMe_M.2_SSD_1_TB/7.html</a><br>
<br>
Thanks. Quite interesting. I hope your heat sink helps.<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">I think it will help some. Transfer speeds aren't all that critical for me at this point but keeping things cooler can't hurt as far as EOL of the component goes.</div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
Looks like a good choice for a drive.<br>
<br>
Something I didn't know:<br>
<br>
=> Thermal throttling is an issue for nearly all M.2 NVMe SSDs,<br>
and the Crucial P1 is no exception. Not cooled and fully<br>
loaded, it will heat up quickly and start throttling after a<br>
bit more than a minute at full load. Now, don't get scared. In<br>
that time, the drive processes almost 100 GB of data. Again,<br>
=> highly unlikely in a consumer scenario. Still, I would have<br>
wished for a higher temperature limit and a more graceful drop<br>
in performance during thermal throttle. Samsung, for example,<br>
has implemented that very well.<br>
<br>
The problem I was thinking of is shown in "write intensive usage":<br>
<br>
<<a href="https://www.techpowerup.com/reviews/Crucial/P1_NVMe_M.2_SSD_1_TB/6.html" rel="noreferrer noreferrer noreferrer" target="_blank">https://www.techpowerup.com/reviews/Crucial/P1_NVMe_M.2_SSD_1_TB/6.html</a>></blockquote></div></div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
But they suggest it hits after 140GB of writes, not 100G you reported:<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">I didn't benchmark the transfer, I only observed the transfer countdown thingy in the file manager. After reading reviews of the drive some M$ users said transfer speed dropped off at around 50gb. My 100gb was me clearing up the WD drive in preparation for Fedora 30, which it is running now.</div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
| > | the SSD. Copying a 100gb image to the 1TB drive really hit performance<br>
| > tho<br>
<br>
You can see a very large performance cliff at 140GB.<br>
<br>
So either what you are observing is not this cliff, or you are doing<br>
something else (reading the image from the drive?) to move the cliff<br>
earlier.<br>
<br>
The heat cliff should be much much sooner, I think.<br>
<br>
Their diagram showed the thermal cliff happened (without any fan)<br>
after about 60 seconds of 160MB/s writing. That would be about 96GB.<br>
Funny that you'd notice that with a 100GB image since only the last<br>
4GB should be slow. That should only take another 7 or 8 seconds<br>
(instead of 2.5 seconds). That isn't something I'd notice.<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">The last few seconds were at 98mb. I didn't actually observe the first few, but in the middle I saw transfer speed start to drop.</div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
Copying a 200 GB image should be a LOT slower than a 100 GB image (if<br>
there is no fan). The second 100GB should take almost 200 seconds.<br>
<br>
After 140GB, the caching cliff should hit. Surprisingly, this doesn't<br>
show up in the article's Thermal Throttling graphs.</blockquote></div></div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
There's something fishy here.<br>
<br>
| > SSDs come with different performance trade-offs. Most inexpensive<br>
| > SSDs have (on-board) controllers with only small amounts of RAM. This<br>
| > makes them slow down a lot after a modest burst of intensive writing.<br>
| > That's a fine trade-off for many of us but not for all workloads.<br>
<br>
The Crucial drive has a 1 GiB RAM chip onboard, not like the cheap ones<br>
I was thinking of.<br>
<br>
I think that the cliff for cheap ones comes much earlier, due to<br>
running out of mapping RAM.<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">Thanks for the link. I had a quick glance and I'll read in depth later.</div><div dir="auto"><br></div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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