Again, this timing problem doesn't seem to be a Lenovo unique problem. These cables are intended to move the bulky SD Card Reader away from the compute so they don't block both ports (which is a real problem with the Y500's two USB ports on the left side). (Transcend, Sandisk, some off-brand) on several different modern laptops (Y500, Z580, Macbook Air 2012-mid) - I have found that SOMETIMES introducing a 120mm USB extension cable between the USB port and the SD Card Reader makes things more reliable. Booting from 3 different models/brands of USB SD Card readers. I have tried 3 other SD Card readers (USB 2.0) in all 3 ports and the problem is the always the same. Int his case, I'm using a Transcend TS-RDF5 USB 3.0 SD Card reader in the left front USB 3.0 port of the Y500.

Note that the 'Atheros Boot Agent' is the first Boot Priority option, before my USB boot device. Here is a photograph of the BIOS setup page so you have some reference of what I'm talking about: I hope eventually they get around to doing so (for Intel i7 Microcode updates and such). Lenovo never seems to release BIOS fixes for this laptop. In my case, no Ethernet cable is actually attached to the system - so the Network Boot delay adds only 1 or 2 seconds to the time as it detects the lack of cable and skips past quickly. It seems putting the Ethernet Atheros Boot Agent first in the boot order gets the BIOS to behave correctly when it comes to booting from the USB device. The freeze happens 100% of the time from a cold system boot and no touching of the keyboard. The typical result is after the Lenovo logo disappears the screen just goes blank and the system is entirely frozen (fan running fast as if the CPU is looping). In legacy BIOS mode, even booting from the eSATA had the same problem for me - moving to GPT and EFI/UEFI booting and the problem disappeared (same mSATA device). THE PROBLEM: The Y500 has a BIOS timing problem. However, sometimes I want to do full system backups and I boot up another Linux from a USB drive. However, I added a Plextor mSATA that is now the primary boot device to get me into GRUB2 and Ubuntu + Fedora Linux (all EFI/UEFI).

My laptop came with a 1TB hard drive, i still have the Windows 8 installed as it came - no changes to partitions. I normally run my system in pure EFI/UEFI mode now.

Lenovo y500 bios update