Wikipedia:Reference desk/Archives/Computing/2018 August 5

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August 5

What are the differences between JEDEC and XMP at the same data rate?

I already know that XMP is Intel's extension to store predefined overclocking settings that are known to be stable, and JEDEC is standard of some sort. XMP is an extension, and the speed/data rate is always higher than JEDEC's of the same module. From what I've heard, the advertised speed is XMP, and all DDR4 modules are 2133MT/s. But for some reason, JEDEC parameters seems to increase as time passes, and I've bought several DDR4 modules with JEDEC 1333Mhz (2666MT/s) yesterday.

What are the differences between a JEDEC 2133 (XMP 2666) module and a JEDEC 2666 module? The obvious thing I can see is that the JEDEC 2666 one works flawlessly out of the box with 4 single rank DIMM installed on my Ryzen 1200 (which only supports 2133-2400 with all 4 DIMMs populated). I've had a hard time to manually get the XMP 2666 modules to work at 2400 with 4 DIMM installed. -- Livy (talk) 05:02, 5 August 2018 (UTC)

The old specification I have found applies to DDR2 memory modules. At the old DIMMs were hardware encoded in operating voltage, a frequency, RAS, and CAS wait states for timing are read out from the I²CEPROM, an 8-pin device on each DIMM, containing this information, called SPD. Intel has developed an additional standard giving more information, called XMP. It allows multiple specifications for the same memory module. It also allows a wider usage of the RAMs, soldered on the memory module. RAMs are selected by voltage and frequency. Tuning them means increasing the speed and sometimes rising the operating voltage to make the rams operate fast enough for the given speed. XMP enables the manufacturers to give more than one operation conditions of the module like save and reliable working at one voltage up to one speed, and a higher voltage in an faster or same speed. The limits are the heat drop on the module, power consumption above, and below the lowest possible voltage he RAMs can operated reliable on high temperature. If there are no other possibilities, the SPD data and the XMP data are identical. This causes one operating condition, only. So XMP can allow the use of cheaper RAMs, dropping voltage an frequency to save power. On the other hand it can allow overclocking and make manufacturers try to offer too hard optimized products which is a less reliable performance for the customers computer. Most of all the overclocking fails due bad performance of the passive parts that fail to stabilize the operating voltage. When overclocking, have the first look on these parts. --Hans Haase (有问题吗) 10:46, 11 August 2018 (UTC)

Privacy Policy Concerns

Hi,

To begin I have been noticing strange activity on some devices, and do not have the knowledge to determine a legitimate process/action from a malicious one. To list strange events:

-apps stating that they cannot run because the privacy policy doesn’t list what it will do with my faceid.

-many debug logs stating there are blank spaces at end of code.

-leanplum folder on devices (no idea)

-shadow socks (not much idea)

-blurry pictures being saved as cookies, possibly including code

-the list goes on...

Can anyone point me to help, and I would also like to learn how to keep these ad companies and others from tracking everything.

Thanks

Dragon Reborne (talk) 16:00, 5 August 2018 (UTC)

@Dragon Reborne: For future reference, state upfront what device you're talking about. I'm guessing from your reference to leanplum and pictures that you're talking about a mobile phone, and to Face ID confirms an iPhone.

Leanplum is a "mobile marketer," which means you've got adware (I don't care if they want to pretend they're anything else, anything they touch is automatically adware). It probably came bundled with something else.

Shadowsocks is for evading internet censorship in China. Did you buy the phone directly from Apple or from a trusted retailer (e.g. Best Buy), or did you buy it through a third party (a seller on Amazon, or a kiosk in the mall)? Because if you bought it from a third party, this opens the door to some potentially concerning possibilities. If you didn't buy the phone from a third party, then some app you installed is up to no good. For now, I'm just going to assume that your iPhone was not hacked before you even bought it:

1) Go through your apps (ignoring the ones that came with the phone) and uninstall ones that you don't use at least five times a week. Again, if you think it came with the phone, leave it alone. If you think it might be a system process, leave it alone (although I'm guessing Apple won't let you uninstall that stuff without jailbreaking but that's at your own risk). Free games and novelty apps are really bad about including adware.

2a) Following these instructions on How To Geek, check the permissions for the remaining apps. Think about why they would need that permission. An app for say, Frogger or Pong, would not need access to your camera (and that might be a sign you need to uninstall that app).

2b) This usually gets rid of most of these problems. If not, you may need to back up everything that you might want to keep, do a factory reset, and the restore your data.

2c) If 2a and 2b do not work, you're going to need to take it to an authorized Apple repair center.

Whether you're reinstalling apps after 2b or 2c, or you're installing new apps after 2a, pay attention to the permissions an app wants before installing it -- if it wants something weird that has nothing to do with the app's intended purpose, find something else. Ian.thomson (talk) 18:24, 5 August 2018 (UTC)

Thanks for the info, and yes it’s iPhoneX purchased on launah from AT&T, but it’s not the only device. Today I encountered even more disturbing events. I found logs that my router has been Telnet into, from the MAC address of my phone. Also http:// is added in search bar no matter what I enter, and url= the L is an I(i). At this point it seems security flaw past my knowledge, and need to wait for the devs who rarely own up to it, patch these things. Apple will tell you the device cannot be remotely accessed but the next update will state it fixes precisely that haha. Anyway I do appreciate the reply.

Dragon Reborne (talk) 06:02, 6 August 2018 (UTC)

This is definitely something specific to your device - like Ian said, probably a bad app you installed. It's not just going to get "patched away." You really need to actively deal with this somehow. If it's an iPhone X you bought at launch, is it still under Apple Care? If so the Apple Store might help you. If not, call up your most technically-able friend, pony up the cash to get it fixed, or backup your important information and factory reset the phone. -Elmer Clark (talk) 21:43, 9 August 2018 (UTC)